Phosphor-containing film and backlight unit

ABSTRACT

Provided are a phosphor-containing capable of suppressing deterioration of phosphors and can be manufactured with high efficiency and a backlight unit. Specifically, provided is a phosphor-containing film, including a first substrate film; and a phosphor-containing layer at which a plurality of regions containing phosphors, which, if exposed to oxygen, deteriorate by reacting with the oxygen, are discretely disposed on the first substrate film, and at which a resin layer having an impermeability to oxygen is disposed between the discretely disposed regions containing phosphors, in which a width S of the resin layer between the regions containing phosphors is 0.01≤S&lt;0.5 mm, and wherein a ratio of a volume Vp of the regions containing phosphors, to a sum of the volume Vp and a volume Vb of the resin layer in the phosphor-containing layer, is 0.1≤Vp/(Vp+Vb)&lt;0.9.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a Continuation patent application of U.S.patent application Ser. No. 15/869,469, filed Jan. 12, 2018, which is aContinuation of International Application No. PCT/JP2016/003654, filedon Aug. 8, 2016, which was published under PCT Article 21(2) inJapanese, which is based upon and claims the benefit of priority fromJapanese Patent Application No. 2015-158044, filed on Aug. 10, 2015, thecontents of all of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a phosphor-containing film containingphosphors that emit fluorescence upon irradiation with excitation lightand a backlight unit including the phosphor-containing film as awavelength converting member.

2. Description of the Related Art

Applications of a flat panel display such as a liquid crystal display(LCD) (hereinafter, also referred to as “LCD”) as a space-saving imagedisplay device with low power consumption have been widespread year byyear. In recent liquid crystal displays, further power saving, anenhancement in color reproducibility, or the like is required as animprovement in LCD performance.

Along with power saving of LCD backlight, in order to increase the lightutilization efficiency and improve the color reproducibility, it hasbeen proposed to use a wavelength converting layer containing a quantumdot (QD, also referred to as a quantum point) that converts a wavelengthof incident light and emits the wavelength-converted light, as aluminescent material (phosphor).

The quantum dot is a state of an electron whose movement direction isrestricted in all directions three-dimensionally. In the case wherenanoparticles of a semiconductor are three-dimensionally surrounded by ahigh potential barrier, the nanoparticles become quantum dots. Thequantum dot expresses various quantum effects. For example, a “quantumsize effect” is expressed in which a density of electronic states(energy level) is discretized. According to this quantum size effect,the absorption wavelength and luminescence wavelength of light can becontrolled by changing the size of a quantum dot.

Generally, such quantum dots are dispersed in a resin or the like, andused as a quantum dot film for wavelength conversion, for example, bybeing disposed between a backlight and a liquid crystal panel.

In the case where excitation light is incident from a backlight to afilm containing quantum dots, the quantum dots are excited to emitfluorescence. Here, white light can be realized by using quantum dotshaving different luminescence properties and causing each quantum dot toemit light having a narrow half width of red light, green light or bluelight. Since the fluorescence by the quantum dot has a narrow halfwidth, wavelengths can be properly selected to thereby allow theresulting white light to be designed so that the white light is high inluminance and excellent in color reproducibility.

Meanwhile, there are problems that quantum dots are susceptible todeterioration due to moisture or oxygen, and particularly theluminescence intensity thereof decreases due to a photooxidationreaction. Therefore, the wavelength converting member is configured insuch a manner that gas barrier films are laminated on both main surfacesof a resin layer containing quantum dots (hereinafter, also referred toas a “quantum dot layer”) which is a wavelength converting layercontaining quantum dots, thereby protecting the quantum dot layer.

However, merely protecting both main surfaces of the quantum dot layerwith gas barrier films has a problem in which moisture or oxygen entersfrom the end face not protected by the gas barrier film, and thereforethe quantum dots deteriorate.

Therefore, it has been proposed to protect the entire periphery of thequantum dot layer with a barrier film.

For example, JP2010-061098A discloses a quantum dot wavelengthconverting structure including a wavelength converting portioncontaining quantum dots for wavelength-converting excitation light togenerate wavelength-converted light and a dispersion medium fordispersing the quantum dots, and a sealing member for sealing thewavelength converting portion, in which the wavelength convertingportion is disposed between two sealing sheets which are sealingmembers, and the peripheries of the wavelength converting portion in thesealing sheets are heated and thermally adhered to each other, therebysealing the wavelength converting portion.

Further, JP2009-283441A discloses a light emitting device including acolor conversion layer (phosphor layer) for converting at least a partof color light emitted from a light source portion into another colorlight and a water impermeable sealing sheet for sealing the colorconversion layer, and discloses a color conversion sheet (phosphorsheet) in which penetration of water into the color conversion layer isprevented by a configuration where the sheet has a second bonding layerprovided in a frame shape along the outer periphery of the phosphorlayer, that is, so as to surround the planar shape of the colorconversion layer, and the second bonding layer is formed of an adhesivematerial having water vapor barrier properties.

SUMMARY OF THE INVENTION

Meanwhile, the wavelength converting layer containing quantum dots usedfor LCDs is a thin film of about 50 μm to 350 μm in thickness. There areproblems that it is extremely difficult to coat the entire surface ofsuch a very thin film with a sealing sheet such as a gas barrier film,thereby leading to poor productivity.

Such problems occur not only in quantum dots, but also in aphosphor-containing film having a phosphor which reacts with oxygen anddeteriorates.

On the other hand, in order to produce a phosphor-containing filmcontaining a phosphor such as a quantum dot with high productionefficiency, preferred is a method of successively applying a coatingstep and a curing step on a long film by a roll-to-roll method to form alaminated structure and then cutting the resulting structure to adesired size.

However, in the case of obtaining a phosphor-containing film of adesired size by cutting from this long film, the phosphor-containinglayer is again exposed to the outside air at the cut end face, so it isnecessary to take measures against entry of oxygen from the cut endface.

The present invention has been made in view of the above circumstances.Accordingly, it is an object of the present invention to provide aphosphor-containing film which contains a phosphor such as a quantumdot, is capable of suppressing deterioration of the phosphor, and isalso suitable for the production by a roll-to-roll method. Anotherobject of the present invention is to provide a backlight unit includinga phosphor-containing film with suppressed luminance deterioration as awavelength converting member.

The phosphor-containing film of the present invention is aphosphor-containing film, comprising:

a first substrate film; and

a phosphor-containing layer at which a plurality of regions containingphosphors, which, if exposed to oxygen, deteriorate by reacting with theoxygen, are discretely disposed on the first substrate film, and atwhich a resin layer having an impermeability to oxygen is disposedbetween the discretely disposed regions containing phosphors,

in which a width S of the resin layer between the regions containingphosphors is 0.01≤S<0.5 mm, and

wherein a ratio of a volume Vp of the regions containing phosphors, to asum of the volume Vp and a volume Vb of the resin layer in thephosphor-containing layer, is 0.1≤Vp/(Vp+Vb)<0.9.

As used herein, the phrase “having an impermeability to oxygen” meansthat the oxygen permeability is 10 cc/(m²·day·atm) or less. The oxygenpermeability of the resin layer is defined as an oxygen permeability atthe shortest distance between the adjacent regions containing phosphors.Note that 1 cc/(m²·day·atm)=1.14×10⁻¹⁶ m/s·Pa.

In the phosphor-containing film of the present invention, the oxygenpermeability of the resin layer is preferably 1 cc/(m²·day·atm) or less.

In the phosphor-containing film of the present invention, the oxygenpermeability of the first substrate film is preferably 10cc/(m²·day·atm) or less.

In the phosphor-containing film of the present invention, it ispreferred that the resin contained in the resin layer is formed of acomposition containing light-scattering particles and a compound havinga photo- or heat-polymerizable functional group.

The phosphor-containing film of the present invention may include asecond substrate film disposed opposite to the first substrate film withthe phosphor-containing layer being interposed therebetween.

It is preferred that the oxygen permeability of the second substratefilm is 10 cc/(m²·day·atm) or less.

The backlight unit of the present invention is a backlight unitincluding a wavelength converting member formed of thephosphor-containing film of the present invention and a blue lightemitting diode or ultraviolet light emitting diode.

The phosphor-containing film of the present invention is formed of afirst substrate film, and a phosphor-containing layer at which aplurality of regions containing phosphors, which, if exposed to oxygen,deteriorate by reacting with the oxygen, are discretely disposed on thefirst substrate film, and at which a resin layer having animpermeability to at least oxygen is filled between the discretelydisposed regions containing phosphors. According to thephosphor-containing film of the present invention, since each regioncontaining phosphors is surrounded by a resin having an impermeabilityto oxygen in the direction along the film surface, it is possible toeffectively suppress penetration of oxygen in the film surface directionfrom the end face to the region containing phosphors other than theregion containing phosphors existing at the end face position. Thephosphor-containing film of the present invention is suitable for aproduction method by a roll-to-roll method, and in the case where aphosphor-containing film of a desired size is produced by cutting from along film, since the penetration of oxygen from the cut end face to theregion containing phosphors inside is effectively suppressed, there isno need to perform another sealing treatment or the like for end facesat the time of cutting, whereby it is possible to further improve theproduction efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a phosphor-containing film of a firstembodiment.

FIG. 2 is a plan view of the phosphor-containing film of the firstembodiment.

FIG. 3 is a cross-sectional view of the phosphor-containing film of thefirst embodiment.

FIG. 4 is a cross-sectional view of a phosphor-containing film of asecond embodiment.

FIG. 5 is a plan view showing an example of a plan view pattern of afluorescent region.

FIG. 6 is a plan view showing another example of the plan view patternof the fluorescent region.

FIG. 7 is a view for explaining a method of specifying a contour of thefluorescent region.

FIG. 8A is a plan view of a phosphor-containing film of a thirdembodiment.

FIG. 8B is a cross-sectional view taken along line B-B′ of thephosphor-containing film shown in FIG. 8A.

FIG. 8C is a cross-sectional view taken along line C-C′ of thephosphor-containing film shown in FIG. 8A.

FIG. 9A is a plan view of a phosphor-containing film of a fourthembodiment.

FIG. 9B is a cross-sectional view taken along line B-B′ of thephosphor-containing film shown in FIG. 9A.

FIG. 10 is a cross-sectional view of a phosphor-containing film of afifth embodiment.

FIG. 11A is a plan view of a phosphor-containing film of a sixthembodiment.

FIG. 11B is a cross-sectional view taken along line B-B′ of thephosphor-containing film shown in FIG. 11A.

FIG. 12 is a view showing a production process of a phosphor-containingfilm.

FIG. 13 is a view for explaining an example of a phosphor-containingfilm formed in a long film shape.

FIG. 14 is a schematic configuration cross-sectional view of a backlightunit including a phosphor-containing film as a wavelength convertingmember.

FIG. 15 is a schematic configuration cross-sectional view of a liquidcrystal display including a backlight unit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of a phosphor-containing film and a backlightunit including the phosphor-containing film according to the presentinvention will be described with reference to the accompanying drawings.In the drawings of the present specification, the scale of each part isappropriately changed for easy visual recognition. In the presentspecification, the numerical range expressed by using “to” means a rangeincluding numerical values described before and after “to” as a lowerlimit value and an upper limit value, respectively.

<Phosphor-Containing Film>

FIG. 1 is a perspective view showing a schematic configuration of aphosphor-containing film 1 according to a first embodiment of thepresent invention, FIG. 2 is a plan view of the phosphor-containing film1, and FIG. 3 is a cross-sectional view showing the detailedconfiguration of the phosphor-containing film 1. The phosphor-containingfilm 1 of the present embodiment includes a first substrate film 10, anda phosphor-containing layer 30 at which a plurality of regions 35containing phosphors 31, which, if exposed to oxygen, deteriorate byreacting with the oxygen, are discretely disposed on the first substratefilm 10, and at which a resin layer 38 having an impermeability tooxygen is disposed between the discretely disposed regions 35 containingphosphors 31. Hereinafter, the region 35 containing the phosphors 31 maybe referred to as a fluorescent region 35 in some cases.

In the phosphor-containing film 1, a width S of the resin layer 38between the fluorescent regions 35 is 0.01≤S<0.5 mm, and the ratio of avolume Vp of the fluorescent regions 35 to the sum of the volume Vp anda volume Vb of the resin layer 38 in the phosphor-containing layer 30 is0.1≤Vp/(Vp+Vb)<0.9.

As used herein, the phrase “a plurality of regions containing phosphors,which, if exposed to oxygen, deteriorate by reacting with the oxygen,are discretely disposed on the first substrate film” means that, asshown in FIGS. 1 and 2, in the case of being viewed from the directionperpendicular to the film surface of the first substrate film (in a planview), a plurality of fluorescent regions 35 are disposed in isolationwithout contacting each other in the two-dimensional direction along thefilm surface of the first substrate film 10. In this example, thefluorescent regions 35 are in the form of a cylinder (disk), and eachfluorescent region 35 is isolatedly surrounded by a resin layer 38having an impermeability to oxygen in the two-dimensional directionalong the film surface of the substrate film 10, and the penetration ofoxygen from the two-dimensional direction along the film surface of thesubstrate film 10 into the individual fluorescent regions 35 is blocked.

As used herein, the phrase, “having an impermeability to oxygen” meansthat an oxygen permeability is 10 cc/(m²·day·atm) or less. The oxygenpermeability of the resin layer having an impermeability to oxygen ismore preferably 1 cc/(m²·day·atm) or less and still more preferably 10⁻¹cc/(m²·day·atm) or less. The phrase “having an impermeability” and thephrase “having barrier properties” as used herein are used synonymously.That is, in the present specification, a gas barrier means having animpermeability to a gas, and a water vapor barrier means having animpermeability to water vapor. Further, a layer having an impermeabilityto both of oxygen and water vapor is referred to as a “barrier layer”.

Since the fluorescent regions 35 are discretely disposed in thetwo-dimensional direction, assuming that the phosphor-containing filmshown in FIG. 2 is a part of a long film, whichever portion is linearlycut as indicated by the broken line, the fluorescent region 35 otherthan the fluorescent region 35 which is the cut point can be kept in asealed state surrounded by the resin layer 38.

The fluorescent region 35 is formed by dispersing the phosphors 31 in abinder 33. In the case where the oxygen permeability of the binder 33 islarger than the permeability of the resin layer 38 filled between thefluorescent regions 35, that is, in the case where the binder 33 tendsto permeate oxygen, the effects of the present invention areparticularly remarkable.

Since the conventional phosphor-containing layer is formed by coating aresin containing phosphors in the form of a uniform film, in the casewhere the phosphor-containing layer is manufactured by forming thephosphor-containing film in a long film shape and then cutting it, thecut end face is exposed to the outside air and consequently oxygen andmoisture gradually enter the inside as well as the vicinity of the endface, which may degrade the performance of the phosphors. On the otherhand, in the phosphor-containing layer of the phosphor-containing filmof the present invention, the fluorescent region positioned at the cutpoint (cut end face) is exposed to the outside air and the phosphors inthe fluorescent region react with oxygen to result in deterioration inthe performance thereof, but the other fluorescent regions spaced apartfrom the cut end face can be kept in a state sealed with a resin havingan impermeability to oxygen. Thus, deterioration in the performance ofthe phosphors in the fluorescent regions other than the cut positionscan be suppressed. For example, in FIG. 2, in the case where thephosphor-containing film is cut along the broken line K, the phosphors31 in the region 35K through which the broken line K passes aredeteriorated, but the other regions 35 can be kept in a sealed state.

The substrate film 10 is preferably impermeable to oxygen and may have alaminated structure of a support film 11 and a barrier layer 12 havingan impermeability to oxygen as shown in FIG. 3.

The main surface at the side of the phosphor-containing film on whichthe substrate film 10 is not provided is mainly used by being formed inclose contact with other members. In the case where thephosphor-containing layer 30 of the phosphor-containing film 1 isdisposed in a state sufficiently spaced from the environment containingoxygen such as the atmosphere in the direction perpendicular to the mainsurface, in the phosphor-containing film itself, it is not necessary totake into consideration the penetration of oxygen from the main surfaceside. However, as described hereinbefore, the substrate film 10 of thephosphor-containing film 1 is preferably impermeable to oxygen and morepreferably impermeable to water vapor as well.

FIG. 4 is a schematic cross-sectional view showing a schematicconfiguration of a phosphor-containing film according to a secondembodiment of the present invention. The phosphor-containing film 2 ofthe second embodiment is a configuration in which, in thephosphor-containing film 1 of the first embodiment, a second substratefilm 20 is further provided on the other main surface of thephosphor-containing layer 30 opposite to the main surface of thephosphor-containing layer 30 on which the first substrate film 10 isdisposed. In the case where, like the phosphor-containing film 2, thesubstrate films 10 and 20 are provided on both main surfaces, and eachsubstrate film 10 or 20 is made of a laminated structure of the supportfilm 11 or 21 and the barrier layer 12 or 22, it is possible to preventthe penetration of oxygen into each fluorescent region 35 of thephosphor-containing layer 30 from the main surface and from the endportion even in the case where it is not incorporated in anotherstructure, which is thus preferable.

The size and arrangement pattern of the fluorescent region 35 are notparticularly limited and may be appropriately designed according todesired conditions. In designing, geometric constraints for arrangingthe fluorescent regions apart from each other in a plan view, allowablevalues of the width of the non-light emitting region generated at thetime of cutting, and the like are taken into consideration. Further, forexample, in the case where the printing method is used as one of themethods for forming a fluorescent region to be described later, there isalso a restriction that printing cannot be carried out unless theindividual occupied area (in a plan view) is not less than a certainsize. Furthermore, the shortest distance between adjacent fluorescentregions is required to be a distance capable of achieving an oxygenpermeability of 10 cc/(m²·day·atm) or less. In consideration of these, adesired shape, size and arrangement pattern may be designed.

In the above embodiment, the fluorescent region 35 is cylindrical and iscircular in a plan view, but the shape of the fluorescent region 35 isnot particularly limited. The fluorescent region 35 may be a polygonalprism such as a quadrilateral in a plan view as shown in FIG. 5, or ahexagon in a plan view as shown in FIG. 6. In the above example, thebottom surface of the cylinder or the polygonal prism is disposedparallel to the substrate film surface, but the bottom surface may notnecessarily be disposed parallel to the substrate film surface. Further,the shape of each fluorescent region 35 may be amorphous.

In the case where the boundary between the binder 33 in the fluorescentregion 35 and the resin layer 38 being impermeable to oxygen and beingbetween the fluorescent regions 35 is not clear, as shown in FIG. 7, aline connecting the points on the outside (the side on which thephosphor 31 is not disposed) of the phosphor 31 e positioned at theoutermost position of the region where the phosphor 31 is closelydisposed is considered as the contour m of the fluorescent region 35(the boundary between the fluorescent region 35 and the resin layer 38).The position of the phosphor can be specified by irradiation of thephosphor-containing layer with excitation light to cause the phosphor toemit light, followed by observation with, for example, a confocal lasermicroscope or the like, whereby the contour m of the fluorescent region35 can be specified. In the present specification, the side of acylinder or a polygonal prism is allowed to meander like the contour inFIG. 7.

In the above embodiment, the fluorescent region 35 is periodicallydisposed in a pattern, but it may be non-periodic as long as the desiredperformance is not impaired in the case where a plurality of fluorescentregions 35 are discretely disposed. It is preferred that the fluorescentregion 35 is uniformly distributed over the entire region of thephosphor-containing layer 30 because the in-plane distribution ofluminance is uniform.

In order to obtain a sufficient amount of fluorescence, it is desirableto make the area occupied by the fluorescent region 35 as large aspossible.

The phosphor 31 in the fluorescent region 35 may be of one kind or ofplural kinds. In addition, the phosphor 31 in one fluorescent region 35is regarded as one kind, and a region containing a first phosphor and aregion containing a second phosphor different from the first phosphoramong the plurality of fluorescent regions 35 may be disposedperiodically or non-periodically. The kind of the phosphor may be threeor more.

The phosphor-containing layer 30 may be formed by laminating a pluralityof fluorescent regions 35 in the thickness direction of the film. Suchan example will be briefly described as phosphor-containing films of thethird to sixth embodiments with reference to FIGS. 8A to 11B. The sameelements as those of the phosphor-containing film of the first andsecond embodiments are denoted by the same reference numerals, and thedetailed description thereof is omitted.

FIGS. 8A, 8B, and 8C are respectively a plan view, a cross-sectionalview taken along line B-B′, and a cross-sectional view taken along lineC-C′ of the phosphor-containing film 3 of the third embodiment.

The phosphor-containing film 3 of the present embodiment includes, as afluorescent region, a first fluorescent region 35 a in which the firstphosphors 31 a are dispersed in the binder 33 and a second fluorescentregion 35 b in which the second phosphors 31 b different from the firstphosphors 31 a are dispersed in the binder 33. The first fluorescentregion 35 a and the second fluorescent region 35 b are alternatelydisposed in a plan view and are dispersed at different positions in thefilm thickness direction. The first fluorescent region 35 a is disposedon the main surface side opposite to the substrate film 10 and thesecond fluorescent region 35 b is disposed on the main surface sideadjacent to the substrate film 10, and the first fluorescent region 35 aand the second fluorescent region 35 b are disposed so as not to overlapeach other in a plan view.

The first phosphor 31 a and the second phosphor 31 b are, for example,phosphors having luminescence center wavelengths different from eachother. For example, a phosphor having an luminescence center wavelengthin a wavelength band of 600 to 680 nm is used as the first phosphor 31a, and a phosphor having an luminescence center wavelength in awavelength band of 520 to 560 nm is used as the second phosphor 31 b,and so on.

Although the binder 33 of the first fluorescent region 35 a and thesecond fluorescent region 35 b is made of the same composition in thisexample, it may be made of a different composition.

FIGS. 9A and 9B are respectively a plan view and a cross-sectional viewtaken along line B-B′ of the phosphor-containing film 4 of the fourthembodiment.

The phosphor-containing film 4 of the present embodiment is differentfrom the phosphor-containing film of the third embodiment in that thefirst fluorescent region 35 a and the second fluorescent region 35 bdisposed at different positions in the film thickness directionpartially overlap each other in the case where the film surface isviewed in a plan view. In this manner, the fluorescent region 35 a andthe fluorescent region 35 b disposed at different positions in the filmdirection may overlap each other in a plan view.

FIG. 10 is a cross-sectional view of the phosphor-containing film 5 ofthe fifth embodiment.

The phosphor-containing film 5 of the present embodiment is the same asthe phosphor-containing film 1 of the first embodiment shown in FIG. 2in a plan view. On the other hand, the phosphor-containing film 5 of thepresent embodiment is different from the phosphor-containing film 5 ofthe first embodiment in which the fluorescent region 35 has a singlelayer structure in that the first fluorescent region 35 a and the secondfluorescent region 35 b are laminated in the film thickness direction.

FIGS. 11A and 11B are respectively a plan view and a cross-sectionalview taken along line B-B′ of the phosphor-containing film 6 of thesixth embodiment.

The phosphor-containing film 6 of the present embodiment has a step-likefluorescent region 35 in which quadrangular prism-shaped regions arelaminated with a shift of a half cycle. In the fluorescent region 35,the first phosphors 31 a and the second phosphors 31 b are dispersed inthe binder 33. In this example, the second phosphors 31 b are dispersedin the lower step portion of the step-like fluorescent region 35 and thefirst phosphors 31 a are dispersed in the upper step portion of thestep-like fluorescent region 35, but the first phosphors 31 a and thesecond phosphors 31 b may be mixed in the entire upper and lower stepportions in the fluorescent region 35.

As described above, in the phosphor-containing film of the presentinvention, the shape of the fluorescent region 35 and the arrangementpattern thereof are not particularly limited. The fluorescent regionsare discretely disposed on the film surface in any case, so that thephosphor in the fluorescent region at the cut end portion isdeteriorated but the fluorescent region in the portion other than thecut end portion is sealed by being surrounded with a oxygen-impermeableresin in the direction along the film surface. Consequently, it ispossible to obtain an effect of suppressing deterioration in performancedue to the penetration of oxygen from the direction along the filmsurface.

Hereinafter, individual constituent elements of the phosphor-containingfilm of the present invention will be described.

The phosphor-containing film 1 is a laminated film in which thephosphor-containing layer 30 is laminated on one film surface of thefirst substrate film 10. As described above, the second substrate film20 may be further provided, and the phosphor-containing layer 30 may besandwiched between two substrate films 10 and 20.

—Phosphor-Containing Layer—

The phosphor-containing layer 30 includes a region 35 containing aplurality of phosphors 31 and a resin layer 38 impermeable to oxygen andfilled between the regions 35.

<<Region Containing Phosphors (Fluorescent Region)>>

The fluorescent region 35 is constituted of phosphors 31 and a binder 33in which the phosphors 31 are dispersed and is formed by applying andcuring a fluorescent region-forming coating liquid containing thephosphors 31 and a curable compound.

<Phosphor>

Various known phosphors can be used as a phosphor which, if exposed tooxygen, deteriorates by reacting with the oxygen. Examples of thephosphor include inorganic phosphors such as rare earth doped garnet,silicates, aluminates, phosphates, ceramic phosphors, sulfide phosphors,and nitride phosphors, and organic fluorescent substances includingorganic fluorescent dyes and organic fluorescent pigments. In addition,phosphors with rare earth-doped semiconductor fine particles, andsemiconductor nanoparticles (quantum dots and quantum rods) are alsopreferably used. A single kind of phosphor may be used alone, but aplurality of phosphors having different wavelengths may be mixed andused so as to obtain a desired fluorescence spectrum, or a combinationof phosphors of different material constitutions (for example, acombination of a rare earth doped garnet and quantum dots) may be used.

As used herein, the phrase “exposed to oxygen” means exposure to anenvironment containing oxygen, such as in the atmosphere, and the phrase“deteriorate by reacting with the oxygen” means that the phosphor isoxidized so that the performance of the phosphor deteriorates(decreases) and refers to mainly the luminescence performance decliningas compared with that before the reaction with oxygen, and in the casewhere the phosphor is used as a photoelectric conversion element, such aphrase means that the photoelectric conversion efficiency declines ascompared with that before the reaction with oxygen.

In the following description, as a phosphor that deteriorates by oxygen,mainly quantum dots will be described as an example. However, thephosphor of the present invention is not limited to quantum dots and isnot particularly limited as long as it is a fluorescent dye thatdeteriorates due to oxygen, or a material that converts energy from theoutside into light or converts light into electricity, such as aphotoelectric conversion material.

(Quantum Dot)

The quantum dot is a fine particle of a compound semiconductor having asize of several nm to several tens of nm and is at least excited byincident excitation light to emit fluorescence.

The phosphor of the present embodiment may include at least one quantumdot or may include two or more quantum dots having differentluminescence properties. Known quantum dots include a quantum dot (A)having a luminescence center wavelength in a wavelength band in therange of 600 nm or more and 680 nm or less, a quantum dot (B) having aluminescence center wavelength in a wavelength band in the range of 500nm or more to less than 600 nm, and a quantum dot (C) having aluminescence center wavelength in a wavelength band in the range of 400nm or more to less than 500 nm, and the quantum dot (A) is excited byexcitation light to emit red light, the quantum dot (B) is excited byexcitation light to emit green light, and the quantum dot (C) is excitedby excitation light to emit blue light. For example, in the case whereblue light is incident as excitation light to a phosphor-containinglayer containing the quantum dot (A) and the quantum dot (B), red lightemitted from the quantum dot (A), green light emitted from the quantumdot (B) and blue light penetrating through the phosphor-containing layercan realize white light. Alternatively, ultraviolet light can beincident as excitation light to a phosphor-containing layer containingthe quantum dots (A), (B), and (C), thereby allowing red light emittedfrom the quantum dot (A), green light emitted from the quantum dot (B),and blue light emitted from the quantum dot (C) to realize white light.

With respect to the quantum dot, reference can be made to, for example,paragraphs [0060] to [0066] of JP2012-169271A, but the quantum dot isnot limited to those described therein. As the quantum dot, commerciallyavailable products can be used without any limitation. The luminescencewavelength of the quantum dot can usually be adjusted by the compositionand size of the particles.

The quantum dot can be added in an amount of, for example, about 0.1 to10 parts by mass with respect to 100 parts by mass of the total amountof the coating liquid.

The quantum dots may be added into the coating liquid in the form ofparticles or in the form of a dispersion liquid in which the quantumdots are dispersed in an organic solvent. It is preferred that thequantum dots be added in the form of a dispersion liquid, from theviewpoint of suppressing aggregation of quantum dot particles. Theorganic solvent used for dispersing the quantum dots is not particularlylimited.

As the quantum dots, for example, core-shell type semiconductornanoparticles are preferable from the viewpoint of improving durability.As the core, Group II-VI semiconductor nanoparticles, Group III-Vsemiconductor nanoparticles, multi-component semiconductornanoparticles, and the like can be used. Specific examples thereofinclude, but are not limited to, CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, InP,InAs, and InGaP. Among them, CdSe, CdTe, InP, InGaP are preferable fromthe viewpoint of emitting visible light with high efficiency. As theshell, CdS, ZnS, ZnO, GaAs, and complexes thereof can be used, but it isnot limited thereto. The luminescence wavelength of the quantum dot canusually be adjusted by the composition and size of the particles.

The quantum dot may be a spherical particle or may be a rod-likeparticle also called a quantum rod, or may be a tetrapod-type particle.A spherical quantum dot or rod-like quantum dot (that is, a quantum rod)is preferable from the viewpoint of narrowing a full width at halfmaximum (FWHM) and enlarging the color reproduction range of a liquidcrystal display.

<Binder in Fluorescent Region, and Curable Compound that Forms ResinLayer Having an Impermeability to Oxygen>

A compound having a polymerizable group can be widely adopted as thecurable compound. The type of the polymerizable group is notparticularly limited and is preferably a (meth)acrylate group, a vinylgroup, or an epoxy group, more preferably a (meth)acrylate group, andstill more preferably an acrylate group. With respect to a polymerizablemonomer having two or more polymerizable groups, the respectivepolymerizable groups may be the same or different.

—(Meth)Acrylate-Based Compounds—

From the viewpoint of transparency, adhesiveness, or the like of a curedfilm after curing, a (meth)acrylate compound such as a monofunctional orpolyfunctional (meth)acrylate monomer, a polymer or prepolymer thereof,or the like is preferable. In the present invention and the presentspecification, the term “(meth)acrylate” is used to mean at least one orany one of acrylate and methacrylate. The same applies to the term“(meth)acryloyl” and the like.

—Difunctional Ones—

The polymerizable monomer having two polymerizable groups may be, forexample, a difunctional polymerizable unsaturated monomer having twoethylenically unsaturated bond-containing groups. The difunctionalpolymerizable unsaturated monomer is suitable for allowing a compositionto have a low viscosity. In the present embodiment, preferred is a(meth)acrylate-based compound which is excellent in reactivity and whichhas no problems associated with a remaining catalyst and the like.

In particular, neopentyl glycol di(meth)acrylate, 1,9-nonanedioldi(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropyleneglycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate,hydroxypivalate neopentyl glycol di(meth)acrylate, polyethylene glycoldi(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, dicyclopentanyl di(meth)acrylate, or the like issuitably used in the present invention.

The amount of the difunctional (meth)acrylate monomer to be used ispreferably 5 parts by mass or more and more preferably 10 to 80 parts bymass with respect to 100 parts by mass of the total amount of thecurable compound contained in the coating liquid, from the viewpoint ofadjusting the viscosity of the coating liquid to a preferable range.

—Tri- or Higher Functional Ones—

The polymerizable monomer having three or more polymerizable groups maybe, for example, a polyfunctional polymerizable unsaturated monomerhaving three or more ethylenically unsaturated bond-containing groups.Such a polyfunctional polymerizable unsaturated monomer is excellent interms of imparting mechanical strength. In the present embodiment,preferred is a (meth)acrylate-based compound which is excellent inreactivity and which has no problems associated with a remainingcatalyst and the like.

Specifically, epichlorohydrin (ECH)-modified glycerol tri(meth)acrylate,ethylene oxide (EO)-modified glycerol tri(meth)acrylate, propylene oxide(PO)-modified glycerol tri(meth)acrylate, pentaerythritol triacrylate,pentaerythritol tetraacrylate, EO-modified phosphoric acid triacrylate,trimethylolpropane tri(meth)acrylate, caprolactone-modifiedtrimethylolpropane tri(meth)acrylate, EO-modified trimethylolpropanetri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate,tris(acryloxyethyl)isocyanurate, dipentaerythritol hexa(meth)acrylate,dipentaerythritol penta(meth)acrylate, caprolactone-modifieddipentaerythritol hexa(meth)acrylate, dipentaerythritolhydroxypenta(meth)acrylate, alkyl-modified dipentaerythritolpenta(meth)acrylate, dipentaerythritol poly(meth)acrylate,alkyl-modified dipentaerythritol tri(meth)acrylate, ditrimethylolpropanetetra(meth)acrylate, pentaerythritolethoxy tetra(meth)acrylate,pentaerythritol tetra(meth)acrylate, or the like is suitable.

Among them, EO-modified glycerol tri(meth)acrylate, PO-modified glyceroltri(meth)acrylate, trimethylolpropane tri(meth)acrylate, EO-modifiedtrimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropanetri(meth)acrylate, dipentaerythritol hexa(meth)acrylate,dipentaerythritol penta(meth)acrylate, pentaerythritolethoxytetra(meth)acrylate, or pentaerythritol tetra(meth)acrylate is suitablyused in the present invention.

The amount of the polyfunctional (meth)acrylate monomer to be used ispreferably 5 parts by mass or more from the viewpoint of the coatingfilm strength of the fluorescent-containing layer after curing, andpreferably 95 parts by mass or less from the viewpoint of suppressinggelation of the coating liquid, with respect to 100 parts by mass of thetotal amount of the curable compound contained in the coating liquid.

—Monofunctional Ones—

A monofunctional (meth)acrylate monomer may be, for example, acrylicacid or methacrylic acid, or derivatives thereof, more specifically, amonomer having one polymerizable unsaturated bond ((meth)acryloyl group)of (meth)acrylic acid in the molecule. Specific examples thereof includethe following compounds, but the present embodiment is not limitedthereto.

Examples include alkyl (meth)acrylates having 1 to 30 carbon atoms inthe alkyl group, such as methyl (meth)acrylate, n-butyl (meth)acrylate,isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl(meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, andstearyl (meth)acrylate; aralkyl (meth)acrylates having 7 to 20 carbonatoms in the aralkyl group, such as benzyl (meth)acrylate; alkoxyalkyl(meth)acrylates having 2 to 30 carbon atoms in the alkoxyalkyl group,such as butoxyethyl (meth)acrylate; aminoalkyl (meth)acrylates having 1to 20 carbon atoms in total in the (monoalkyl or dialkyl)aminoalkylgroup, such as N,N-dimethylaminoethyl (meth)acrylate; polyalkyleneglycol alkyl ether (meth)acrylates having 1 to 10 carbon atoms in thealkylene chain and having 1 to 10 carbon atoms in the terminal alkylether, such as diethylene glycol ethyl ether (meth)acrylate, triethyleneglycol butyl ether (meth)acrylate, tetraethylene glycol monomethyl ether(meth)acrylate, hexaethylene glycol monomethyl ether (meth)acrylate,octaethylene glycol monomethyl ether (meth)acrylate, nonaethylene glycolmonomethyl ether (meth)acrylate, dipropylene glycol monomethyl ether(meth)acrylate, heptapropylene glycol monomethyl ether (meth)acrylate,and tetraethylene glycol monoethyl ether (meth)acrylate; polyalkyleneglycol aryl ether (meth)acrylates having 1 to 30 carbon atoms in thealkylene chain and having 6 to 20 carbon atoms in the terminal arylether, such as hexaethylene glycol phenyl ether (meth)acrylate;(meth)acrylates having an alicyclic structure and having 4 to 30 carbonatoms in total, such as cyclohexyl (meth)acrylate, dicyclopentanyl(meth)acrylate, isobornyl (meth)acrylate, and methylene oxide additioncyclodecatriene (meth)acrylate; fluorinated alkyl (meth)acrylates having4 to 30 carbon atoms in total, such as heptadecafluorodecyl(meth)acrylate; (meth)acrylates having a hydroxyl group, such as2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate,4-hydroxybutyl (meth)acrylate, triethylene glycol mono(meth)acrylate,tetraethylene glycol mono(meth)acrylate, hexaethylene glycolmono(meth)acrylate, octapropylene glycol mono(meth)acrylate, andglycerol mono or di(meth)acrylate; (meth)acrylates having a glycidylgroup, such as glycidyl (meth)acrylate; polyethylene glycolmono(meth)acrylates having 1 to 30 carbon atoms in the alkylene chain,such as tetraethylene glycol mono(meth)acrylate, hexaethylene glycolmono(meth)acrylate, and octapropylene glycol mono(meth)acrylate; and(meth)acrylamides such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropyl (meth)acrylamide, 2-hydroxyethyl(meth)acrylamide, and acryloylmorpholine.

The amount of the monofunctional (meth)acrylate monomer to be used ispreferably 10 parts by mass or more and more preferably 10 to 80 partsby mass with respect to 100 parts by mass of the total amount of thecurable compound contained in the coating liquid, from the viewpoint ofadjusting the viscosity of the coating liquid to a preferable range.

—Epoxy-Based Compounds and Others—

The polymerizable monomer for use in the present embodiment may be, forexample, a compound having a cyclic group such as a ring-openingpolymerizable cyclic ether group such as an epoxy group or an oxetanylgroup. Such a compound may be more preferably, for example, a compoundhaving a compound (epoxy compound) having an epoxy group. Use of thecompound having an epoxy group or an oxetanyl group in combination withthe (meth)acrylate-based compound tends to improve adhesiveness to thebarrier layer.

Examples of the compound having an epoxy group include polyglycidylesters of polybasic acids, polyglycidyl ethers of polyhydric alcohols,polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyl ethers ofaromatic polyols, hydrogenated compounds of polyglycidyl ethers ofaromatic polyols, urethane polyepoxy compounds, and epoxidizedpolybutadienes. These compounds may be used alone or in combination oftwo or more thereof.

Examples of other compounds having an epoxy group, which may bepreferably used, include aliphatic cyclic epoxy compounds, bisphenol Adiglycidyl ethers, bisphenol F diglycidyl ethers, bisphenol S diglycidylethers, brominated bisphenol A diglycidyl ethers, brominated bisphenol Fdiglycidyl ethers, brominated bisphenol S diglycidyl ethers,hydrogenerated bisphenol A diglycidyl ethers, hydrogenerated bisphenol Fdiglycidyl ethers, hydrogenerated bisphenol S diglycidyl ethers,1,4-butanediol diglycidyl ethers, 1,6-hexanediol diglycidyl ethers,glycerin triglycidyl ethers, trimethylolpropane triglycidyl ethers,polyethylene glycol diglycidyl ethers, and polypropylene glycoldiglycidyl ethers; polyglycidyl ethers of polyether polyols, obtained byadding one or two or more alkylene oxides to an aliphatic polyhydricalcohol such as ethylene glycol, propylene glycol, or glycerin;diglycidyl esters of aliphatic long chain dibasic acids; monoglycidylethers of aliphatic higher alcohols; monoglycidyl ethers of polyetheralcohols, obtained by adding an alkylene oxide to phenol, cresol, butylphenol, or these compounds; and glycidyl esters of higher fatty acids.

Among these components, aliphatic cyclic epoxy compounds, bisphenol Adiglycidyl ethers, bisphenol F diglycidyl ethers, hydrogeneratedbisphenol A diglycidyl ethers, hydrogenerated bisphenol F diglycidylethers, 1,4-butanediol diglycidyl ethers, 1,6-hexanediol diglycidylethers, glycerin triglycidyl ethers, trimethylolpropane triglycidylethers, neopentyl glycol diglycidyl ethers, polyethylene glycoldiglycidyl ethers, and polypropylene glycol diglycidyl ethers arepreferable.

Examples of commercially available products which can be suitably usedas the compound having an epoxy group or an oxetanyl group includeUVR-6216 (manufactured by Union Carbide Corporation), glycidol, AOEX24,CYCLOMER A200, CELLOXIDE 2021P and CELLOXIDE 8000 (all manufactured byDaicel Corporation), 4-vinylcyclohexene dioxide manufactured by SigmaAldrich, Inc., EPIKOTE 828, EPIKOTE 812, EPIKOTE 1031, EPIKOTE 872 andEPIKOTE CT508 (all manufactured by Yuka Shell Epoxy K.K.), and KRM-2400,KRM-2410, KRM-2408, KRM-2490, KRM-2720 and KRM-2750 (all manufactured byAsahi Denka Kogyo K.K.). These compounds may be used alone or incombination of two or more thereof.

Although there are no particular restrictions on the production methodof such a compound having an epoxy group or an oxetanyl group, thecompound can be synthesized with reference to, for example, Literaturessuch as Fourth Edition Experimental Chemistry Course 20 OrganicSynthesis II, p. 213˜, 1992, published by Maruzen K K; Ed. by AlfredHasfner, The chemistry of heterocyclic compounds-Small Ring Heterocyclespart 3 Oxiranes, John & Wiley and Sons, An Interscience Publication, NewYork, 1985, Yoshimura, Adhesion, vol. 29, No. 12, 32, 1985, Yoshimura,Adhesion, vol. 30, No. 5, 42, 1986, Yoshimura, Adhesion, vol. 30, No. 7,42, 1986, JP2001-100378A (JP-H11-100378A), JP2906245B, and JP2926262B.

For the curable compound for use in the present embodiment, a vinylether compound may also be used.

As the vinyl ether compound, a known vinyl ether compound can beappropriately selected, and, for example, the compound described inparagraph [0057] of JP2009-73078A may be preferably adopted.

Such a vinyl ether compound can be synthesized by, for example, themethod described in Stephen. C. Lapin, Polymers Paint Color Journal. 179(4237), 321 (1988), namely, by a reaction of a polyhydric alcohol or apolyhydric phenol with acetylene, or a reaction of a polyhydric alcoholor a polyhydric phenol with a halogenated alkyl vinyl ether, and suchmethod and reactions may be used alone or in combination of two or morethereof.

For the coating liquid in the present embodiment, a silsesquioxanecompound having a reactive group described in JP2009-73078A can also beused from the viewpoint of a decrease in viscosity and an increase inhardness.

The curable compound for forming the resin layer 38 having animpermeability to oxygen is particularly preferably a compound capableof forming a resin layer having high gas barrier properties, such as a(meth)acrylate-based compound or an epoxy-based compound.

Among the foregoing curable compounds, a (meth)acrylate compound ispreferable from the viewpoint of composition viscosity andphotocurability, and acrylate is more preferable. In the presentinvention, a polyfunctional polymerizable compound having two or morepolymerizable functional groups is preferable. In the present invention,particularly, the compounding ratio of the monofunctional (meth)acrylatecompound to the polyfunctional (meth)acrylate compound is preferably80/20 to 0/100, more preferably 70/30 to 0/100, and still morepreferably 40/60 to 0/100 in terms of weight ratio. By selecting anappropriate ratio, it is possible to provide sufficient curability andmake the composition low in viscosity.

The ratio of the difunctional (meth)acrylate to the trifunctional orhigher functional (meth)acrylate in the polyfunctional (meth)acrylatecompound is preferably 100/0 to 20/80, more preferably 100/0 to 50/50,and still more preferably 100/0 to 70/30 in terms of mass ratio. Sincethe trifunctional or higher functional (meth)acrylate has a higherviscosity than the difunctional (meth)acrylate, a larger amount of thedifunctional (meth)acrylate is preferable because the viscosity of thecurable compound for a resin layer having an impermeability to oxygen inthe present invention can be lowered.

From the viewpoint of enhancing an impermeability to oxygen, it ispreferred to include a compound containing a substituent having anaromatic structure and/or an alicyclic hydrocarbon structure as thepolymerizable compound. The polymerizable compound having an aromaticstructure and/or an alicyclic hydrocarbon structure is more preferablycontained in an amount of 50% by mass or more and still more preferably80% by mass or more. The polymerizable compound having an aromaticstructure is preferably a (meth)acrylate compound having an aromaticstructure. As the (meth)acrylate compound having an aromatic structure,a monofunctional (meth)acrylate compound having a naphthalene structure,such as 1- or 2-naphthyl (meth)acrylate, 1- or 2-naphthylmethyl(meth)acrylate, or 1- or 2-naphthylethyl (meth)acrylate, amonofunctional acrylate having a substituent on the aromatic ring, suchas benzyl acrylate, and a difunctional acrylate such as catecholdiacrylate or xylylene glycol diacrylate are particularly preferable. Asthe polymerizable compound having an alicyclic hydrocarbon structure,isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate,dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate,adamantyl (meth)acrylate, tricyclodecanyl (meth)acrylate,tetracyclododecanyl (meth)acrylate, and the like are preferable.

In addition, in the case where (meth)acrylate is used as thepolymerizable compound, acrylate is preferable to methacrylate from theviewpoint of excellent curability.

The curable compound for forming the resin layer 38 of the presentinvention having an impermeability to oxygen may contain both a(meth)acrylate compound having an aromatic structure and/or an alicyclichydrocarbon structure and a (meth)acrylate having a fluorine atom as thepolymerizable compound. As for the compounding ratio, it is preferredthat 80% by mass or more of the total polymerizable compound componentis a (meth)acrylate compound having an aromatic structure and/or analicyclic hydrocarbon structure, and 0.1 to 10% by mass of the totalpolymerizable compound component is a (meth)acrylate having a fluorineatom. Further, preferred is a blend system in which the (meth)acrylatecompound having an aromatic structure and/or alicyclic hydrocarbonstructure is liquid at 1 atm and 25° C. and the (meth)acrylate having afluorine atom is solid at 1 atm and 25° C.

From the viewpoint of improving the curability and improving theviscosity of the curable compound, the total content of thepolymerizable compound in the curable compound forming the resin layer38 having an impermeability to oxygen is preferably 50 to 99.5% by mass,more preferably 70 to 99% by mass, and particularly preferably 90 to 99%by mass, in all the components excluding the solvent.

More preferably, as for the polymerizable compound component in thecurable compound forming the resin layer 38 having an impermeability tooxygen, with respect to the total polymerizable compound, it ispreferred that the content of the polymerizable compound having aviscosity of 3 to 2,000 mPa·s at 25° C. is 80% by mass or more, it ismore preferred that the content of the polymerizable compound having aviscosity of 5 to 1,000 mPa·s at 25° C. is 80% by mass or more, it isparticularly preferred that the content of the polymerizable compoundhaving a viscosity of 7 to 500 mPa·s at 25° C. is 80% by mass or more,and it is most preferred that the content of the polymerizable compoundhaving a viscosity of 10 to 300 mPa·s at 25° C. is 80% by mass or more.

As for the polymerizable compound included in the curable compoundforming the resin layer 38 having an impermeability to oxygen, it ispreferred that the polymerizable compound, which is liquid at 25° C., is50% by mass or more in the total polymerizable compound, from theviewpoint of temporal stability.

<Thixotropic Agent>

The thixotropic agent is an inorganic compound or an organic compound.

—Inorganic Compound—

One preferred aspect of the thixotropic agent is a thixotropic agent ofan inorganic compound, and, for example, a needle-like compound, achain-like compound, a flattened compound, or a layered compound can bepreferably used. Among them, a layered compound is preferable.

The layered compound is not particularly limited and examples thereofinclude talc, mica, feldspar, kaolinite (kaolin clay), pyrophyllite(pyrophyllite clay), sericite (silk mica), bentonite,smectite-vermiculites (montmorillonite, beidellite, non-tronite,saponite, and the like), organic bentonite, and organic smectite.

These compounds may be used alone or in combination of two or morethereof. Examples of commercially available layered compounds include,as inorganic compounds, CROWN CLAY, BURGESS CLAY #60, BURGESS CLAY KFand OPTIWHITE (all manufactured by Shiraishi Kogyo Kaisha Ltd.), KAOLINJP-100, NN KAOLIN CLAY, ST KAOLIN CLAY AND HARDSEAL (all manufactured byTsuchiya Kaolin Ind., Ltd.), ASP-072, SATINTONPLUS, TRANSLINK 37 andHYDROUSDELAMI NCD (all manufactured by Angel Hard Corporation), SYKAOLIN, OS CLAY, HA CLAY and MC HARD CLAY (all manufactured by MaruoCalcium Co., Ltd.), RUCENTITE SWN, RUCENTITE SAN, RUCENTITE STN,RUCENTITE SEN and RUCENTITE SPN (all manufactured by Co-op Chemical Co.,Ltd.), SUMECTON (manufactured by Kunimine Industries Co., Ltd.), BENGEL,BENGEL FW, ESBEN, ESBEN 74, ORGANITE and ORGANITE T (all manufactured byHojun Co., Ltd.), HODAKA JIRUSHI, ORBEN, 250M, BENTONE 34 and BENTONE 38(all manufactured by Wilbur-Ellis Company), and LAPONITE, LAPONITE RDand LAPONITE RDS (all manufactured by Nippon Silica Industrial Co.,Ltd.). These compounds may also be dispersed in a solvent.

The thixotropic agent to be added to the coating liquid is, amonglayered inorganic compounds, a silicate compound represented byxM(I)₂O.ySiO₂ (also including a compound corresponding to M(II)O orM(III)₂O₃ having an oxidation number of 2 or 3; x and y represent apositive number), and a further preferred compound is a swellablelayered clay mineral such as hectorite, bentonite, smectite, orvermiculite.

Particularly preferably, a layered (clay) compound modified with anorganic cation (a compound in which an interlayer cation such as sodiumin a silicate compound is exchanged with an organic cation compound) canbe suitably used, and examples thereof include compounds in which asodium ion in sodium magnesium silicate (hectorite) is exchanged with anammonium ion which will be described below.

Examples of the ammonium ion include a monoalkyltrimethylammonium ion, adialkyldimethylammonium ion and a trialkylmethylammonium ion, eachhaving an alkyl chain having 6 to 18 carbon atoms, adipolyoxyethylene-palm oil-alkylmethylammonium ion and abis(2-hydroxyethyl)-palm oil-alkylmethylammonium ion, each having 4 to18 oxyethylene chains, and a polyoxypropylene methyldiethylammonium ionhaving 4 to 25 oxopropylene chains. These ammonium ions may be usedalone or in combination of two or more thereof.

The method for producing an organic cation-modified silicate mineral inwhich a sodium ion of sodium magnesium silicate is exchanged with anammonium ion is as follows: sodium magnesium silicate is dispersed inwater and sufficiently stirred, and thereafter allowed to stand for 16hours or more to prepare a 4% by mass dispersion liquid; while thisdispersion liquid is stirred, a desired ammonium salt is added in anamount of 30% by mass to 200% by mass relative to sodium magnesiumsilicate; after the addition, cation exchange takes place, and hectoritecontaining an ammonium salt between the layers becomes insoluble inwater and precipitates, and therefore the precipitate is collected byfiltration and dried. In the preparation, heating may also be carriedout for the purpose of accelerating the dispersion.

Commercially available products of the alkylammonium-modified silicatemineral include RUCENTITE SAN, RUCENTITE SAN-316, RUCENTITE STN,RUCENTITE SEN, and RUCENTITE SPN (all manufactured by Co-op ChemicalCo., Ltd.), which may be used alone or in combination of two or morethereof.

In the present embodiment, silica, alumina, silicon nitride, titaniumdioxide, calcium carbonate, zinc oxide, or the like can be used as thethixotropic agent of an inorganic compound. These compounds may also besubjected to a treatment to adjust hydrophilicity or hydrophobicity onthe surface, as necessary.

—Organic Compound—

For the thixotropic agent, a thixotropic agent of an organic compoundcan be used. Examples of the thixotropic agent of an organic compoundinclude an oxidized polyolefin and a modified urea.

The above-mentioned oxidized polyolefin may be independently preparedin-house or may be a commercially available product. Examples ofcommercially available products include DISPARLON 4200-20 (trade name,manufactured by Kusumoto Chemicals, Ltd.) and FLOWNON SA300 (trade name,manufactured by Kyoeisha Chemical Co., Ltd.).

The above-mentioned modified urea is a reaction product of an isocyanatemonomer or an adduct thereof with an organic amine. The above-mentionedmodified urea may be independently prepared in-house or may be acommercially available product. The commercially available product maybe, for example, BYK 410 (manufactured by BYK).

—Content—

The content of the thixotropic agent in the coating liquid is preferably0.15 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, andparticularly preferably 0.2 to 8 parts by mass, with respect to 100parts by mass of the curable compound. In particular, in the case of thethixotropic agent of an inorganic compound, the content of 20 parts bymass or less with respect to 100 parts by mass of the curable compoundtends to improve brittleness.

<Polymerization Initiator>

The coating liquid may contain a known polymerization initiator as apolymerization initiator. With respect to the polymerization initiator,for example, reference can be made to paragraph [0037] ofJP2013-043382A. The polymerization initiator is preferably in an amountof 0.1% by mol or more and more preferably 0.5 to 2% by mol based on thetotal amount of the curable compound contained in the coating liquid. Inaddition, the polymerization initiator is preferably contained in anamount of 0.1% by mass to 10% by mass and more preferably 0.2% by massto 8% by mass, as the percentage by mass in the total curablecomposition excluding the volatile organic solvent.

—Photopolymerization Initiator—

The curable compound forming the resin layer 38 having an impermeabilityto oxygen preferably contains a photopolymerization initiator. Anyphotopolymerization initiator may be used as long as it is a compoundcapable of generating an active species that polymerizes thepolymerizable compound upon irradiation with light. Examples of thephotopolymerization initiator include a cationic polymerizationinitiator and a radical polymerization initiator, among which a radicalpolymerization initiator is preferable. Further, in the presentinvention, a plurality of photopolymerization initiators may be used incombination.

The content of the photopolymerization initiator is, for example, 0.01to 15% by mass, preferably 0.1 to 12% by mass, and more preferably 0.2to 7% by mass, in the total composition excluding the solvent. In thecase where two or more photopolymerization initiators are used, thetotal content thereof falls within the above-specified range.

In the case where the content of the photopolymerization initiator is0.01% by mass or more, sensitivity (fast curability) and coating filmstrength tend to improve, which is preferable. On the other hand, in thecase where the content of the photopolymerization initiator is 15% bymass or less, light transmittance, colorability, handleability, and thelike tend to improve, which is preferable. In a system including a dyeand/or a pigment, they may act as a radical trapping agent and affectphotopolymerizability and sensitivity. In consideration of this point,in these applications, the addition amount of the photopolymerizationinitiator is optimized. On the other hand, in the composition used inthe present invention, the dye and/or pigment is not an essentialcomponent, and the optimum range of the photopolymerization initiatormay be different from that in the field of a curable composition forliquid crystal display color filter, or the like.

As the radical photopolymerization initiator, for example, acommercially available initiator can be used. The examples thereofinclude those described, for example, in paragraph [0091] ofJP2008-105414A, which are preferably used. Among them, anacetophenone-based compound, an acylphosphine oxide-based compound, andan oxime ester-based compound are preferable from the viewpoint ofcuring sensitivity and absorption properties.

The acetophenone-based compound may be preferably, for example, ahydroxyacetophenone-based compound, a dialkoxyacetophenone-basedcompound, and an aminoacetophenone-based compound. Thehydroxyacetophenone-based compound may be preferably, for example,Irgacure (registered trademark) 2959(1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one,Irgacure (registered trademark) 184 (1-hydroxycyclohexyl phenylketone),Irgacure (registered trademark) 500 (1-hydroxycyclohexyl phenylketone,benzophenone), and Darocur (registered trademark) 1173(2-hydroxy-2-methyl-1-phenyl-1-propan-1-one), all of which arecommercially available from BASF GmbH. The dialkoxyacetophenone-basedcompound may be preferably, for example, Irgacure (registered trademark)651 (2,2-dimethoxy-1,2-diphenylethan-1-one) which is commerciallyavailable from BASF GmbH.

The aminoacetophenone-based compound may be preferably, for example,Irgacure (registered trademark) 369(2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1), Irgacure(registered trademark) 379 (EG)(2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)butan-1-one,and Irgacure (registered trademark) 907(2-methyl-1-[4-methylthiophenyl]-2-morpholinopropan-1-one), all of whichare commercially available from BASF GmbH.

The acylphosphine oxide-based compound may be preferably, for example,Irgacure (registered trademark) 819(bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide), and Irgacure(registered trademark) 1800(bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide), allof which are commercially available from BASF GmbH, and Lucirin TPO(2,4,6-trimethylbenzoyldiphenylphosphine oxide) and Lucirin TPO-L(2,4,6-trimethylbenzoylphenylethoxyphosphine oxide), both of which arecommercially available from BASF GmbH.

The oxime ester-based compound may be preferably, for example, Irgacure(registered trademark) OXE01 (1,2-octanedione,1-[4-(phenylthio)phenyl]-2-(O-benzoyloxime)), Irgacure (registeredtrademark) OXE02 (ethanone,1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, and1-(O-acetyloxime)), all of which are commercially available from BASFGmbH.

The cationic photopolymerization initiator is preferably a sulfoniumsalt compound, an iodonium salt compound, an oxime sulfonate compound,or the like, and examples thereof include4-methylphenyl[4-(1-methylethyl)phenyliodoniumtetrakis(pentafluorophenyl)borate (PI 2074 manufactured by Rhodia),4-methylphenyl[4-(2-methylpropyl)phenyliodonium hexafluorophosphate(IRGACURE 250 manufactured by BASF GmbH), and IRGACURE PAG103, 108, 121,and 203 (all manufactured by BASF GmbH).

The photopolymerization initiator needs to be selected appropriatelywith respect to the wavelength of the light source to be used, but it ispreferred that the photopolymerization initiator does not generate gasduring mold pressurization/exposure. In the case where gas is generated,the mold is contaminated, so it is necessary to frequently clean themold, or the photocurable composition is deformed in the mold, whichcontributes to problems such as deterioration of transfer patternaccuracy.

The curable compound forming the resin layer 38 having an impermeabilityto oxygen is preferably a radical polymerizable curable composition inwhich the polymerizable compound is a radical polymerizable compound andthe photopolymerization initiator is a radical polymerization initiatorthat generates radicals upon irradiation with light.

<Silane Coupling Agent>

The phosphor-containing layer formed from the coating liquid containinga silane coupling agent can exhibit excellent durability due to havingstrong adhesiveness to an adjacent layer due to the silane couplingagent. In addition, the phosphor-containing layer formed from thecoating liquid containing a silane coupling agent is also preferable informing the relationship of adhesion force A between support film andbarrier layer<adhesion force B between phosphor-containing layer andbarrier layer, under adhesion force conditions. This is mainly due tothe fact that the silane coupling agent contained in thephosphor-containing layer forms a covalent bond with the surface of theadjacent layer or the constituent component of the phosphor-containinglayer by hydrolysis reaction or condensation reaction. In the case wherethe silane coupling agent has a reactive functional group such as aradical polymerizable group, the formation of a crosslinking structurewith a monomer component constituting the phosphor-containing layer canalso contribute to an improvement in adhesiveness to the layer adjacentto the phosphor-containing layer.

For the silane coupling agent, a known silane coupling agent can be usedwithout any limitation. From the viewpoint of adhesiveness, a preferredsilane coupling agent may be, for example, a silane coupling agentrepresented by General Formula (1) described in JP2013-43382A.

(In General Formula (1), R₁ to R₆ are each independently a substitutedor unsubstituted alkyl group or aryl group, provided that at least oneof R₁, R₂, R₃, R₄, R₅, or R₆ is a substituent containing a radicalpolymerizable carbon-carbon double bond.)

R₁ to R₆ are preferably an unsubstituted alkyl group or an unsubstitutedaryl group, except for a case where R₁ to R₆ are a substituentcontaining a radical polymerizable carbon-carbon double bond. The alkylgroup is preferably an alkyl group having 1 to 6 carbon atoms and morepreferably a methyl group. The aryl group is preferably a phenyl group.R₁ to R₆ are each particularly preferably a methyl group.

It is preferred that at least one of R₁, R₂, R₃, R₄, R₅, or R₆ has asubstituent containing a radical polymerizable carbon-carbon doublebond, and two of R₁ to R₆ are a substituent containing a radicalpolymerizable carbon-carbon double bond. Further, it is particularlypreferred that among R₁ to R₃, the number of those having a substituentcontaining a radical polymerizable carbon-carbon double bond is 1, andamong R₄ to R₆, the number of those having a substituent containing aradical polymerizable carbon-carbon double is 1.

In the case where the silane coupling agent represented by GeneralFormula (1) has two or more substituents containing a radicalpolymerizable carbon-carbon double, the respective substituents may bethe same or different, and are preferably the same.

It is preferred that the substituent containing a radical polymerizablecarbon-carbon double bond is represented by —X—Y where X is a singlebond, an alkylene group having 1 to 6 carbon atoms, or an arylene group,preferably a single bond, a methylene group, an ethylene group, apropylene group, or a phenylene group; and Y is a radical polymerizablecarbon-carbon double bond group, preferably an acryloyloxy group, amethacryloyloxy group, an acryloylamino group, a methacryloylaminogroup, a vinyl group, a propenyl group, a vinyloxy group, or avinylsulfonyl group, and more preferably a (meth)acryloyloxy group.

R₁ to R₆ may also have a substituent other than the substituentcontaining a radical polymerizable carbon-carbon double bond. Examplesof such a substituent include alkyl groups (for example, a methyl group,an ethyl group, an isopropyl group, a tert-butyl group, a n-octyl group,an n-decyl group, an n-hexadecyl group, a cyclopropyl group, acyclopentyl group, and a cyclohexyl group), aryl groups (for example, aphenyl group and a naphthyl group), halogen atoms (for example,fluorine, chlorine, bromine, and iodine), acyl groups (for example, anacetyl group, a benzoyl group, a formyl group, and a pivaloyl group),acyloxy groups (for example, an acetoxy group, an acryloyloxy group, anda methacryloyloxy group), alkoxycarbonyl groups (for example, amethoxycarbonyl group and an ethoxycarbonyl group), aryloxycarbonylgroups (for example, a phenyloxycarbonyl group), and sulfonyl groups(for example, a methanesulfonyl group and a benzenesulfonyl group).

The silane coupling agent is contained in the coating liquid in therange of preferably 1 to 30% by mass, more preferably 3 to 30% by mass,and still more preferably 5 to 25% by mass, from the viewpoint offurther improving the adhesiveness to the adjacent layer.

The curable compound forming the resin layer 38 having an impermeabilityto oxygen may contain at least one surfactant containing 20% by mass ormore of fluorine atoms.

The surfactant preferably contains 25% by mass or more of fluorine atomsand more preferably 28% by mass or more of fluorine atoms. The upperlimit value of the fluorine atom content is not specifically defined,but it is, for example, 80% by mass or less and preferably 70% by massor less.

The surfactant used in the present invention is preferably a compoundhaving an alkyl group having a fluorine atom, a cycloalkyl group havinga fluorine atom, or an aryl group having a fluorine atom.

The alkyl group containing a fluorine atom is a linear or branched alkylgroup in which at least one hydrogen atom is substituted with a fluorineatom. The alkyl group preferably has 1 to 10 carbon atoms and morepreferably 1 to 4 carbon atoms. The alkyl group containing a fluorineatom may further have a substituent other than a fluorine atom.

The cycloalkyl group containing a fluorine atom is a monocyclic orpolycyclic cycloalkyl group in which at least one hydrogen atom issubstituted with a fluorine atom. The cycloalkyl group containing afluorine atom may further have a substituent other than a fluorine atom.

The aryl group containing a fluorine atom is an aryl group in which atleast one hydrogen atom is substituted with a fluorine atom. Examples ofthe aryl group include a phenyl group and a naphthyl group. The arylgroup containing a fluorine atom may further have a substituent otherthan a fluorine atom.

By having such a structure, it is considered that the surface unevendistribution ability becomes satisfactory, and partial compatibilitywith the polymer occurs and phase separation is suppressed.

The molecular weight of the surfactant is preferably 300 to 10,000 andmore preferably 500 to 5,000.

The content of the surfactant is, for example, 0.01 to 10% by mass,preferably 0.1 to 7% by mass, and more preferably 0.5 to 4% by mass inthe total composition excluding the solvent. In the case where two ormore surfactants are used, the total content thereof falls within theabove-specified range.

Examples of the surfactant include FLUORAD FC-430 and FC-431 (tradenames, manufactured by Sumitomo 3M Ltd.), SURFLON S-382 (trade name,manufactured by Asahi Glass Co., Ltd.), EFTOP “EF-122A, 122B, 122C,EF-121, EF-126, EF-127, and MF-100” (manufactured by Tohkem ProductsCorporation), PF-636, PF-6320, PF-656 and PF-6520 (trade names, allmanufactured by OMNOVA Solutions, Inc.), FTERGENT FT250, FT251 and DFX18(trade names, all manufactured by NEOS Co., Ltd.), UNIDYNE DS-401,DS-403 and DS-451 (trade names, all manufactured by Daikin IndustriesLtd.), MEGAFACE 171, 172, 173, 178K and 178A (trade names, allmanufactured by DIC Corporation), X-70-090, X-70-091, X-70-092 andX-70-093 (trade names, all manufactured by Shin-Etsu Chemical Co.,Ltd.), and MEGAFACE R-08 and XRB-4 (trade names, all manufactured by DICCorporation).

(Other Components)

In addition to the above-mentioned components, the curable compoundforming the resin layer 38 having an impermeability to oxygen maycontain other components such as an antioxidant in accordance withvarious purposes as long as the effects of the present invention are notimpaired.

—Antioxidant—

The curable compound forming the resin layer 38 having an impermeabilityto oxygen preferably contains a known antioxidant. The content of theantioxidant is, for example, 0.01 to 10% by mass and preferably 0.2 to5% by mass, with respect to the total polymerizable monomers. In thecase where two or more antioxidants are used, the total amount thereoffalls within the above-specified range. The antioxidant is forpreventing color fading by heat or photo-irradiation, and for preventingcolor fading by various oxidizing gases such as ozone, active oxygenNO_(X), and SO_(X) (X is an integer). Especially in the presentinvention, addition of the antioxidant brings about advantages that thecured film is prevented from being colored and the film thickness isprevented from being reduced through decomposition. Examples of theantioxidant include hydrazides, hindered amine-based antioxidants,nitrogen-containing heterocyclic mercapto compounds, thioether-basedantioxidants, hindered phenol-based antioxidants, ascorbic acids, zincsulfate, thiocyanates, thiourea derivatives, saccharides, nitrites,sulfites, thiosulfates, and hydroxylamine derivatives. Of those,hindered phenol-based antioxidants and thioether-based antioxidants areparticularly preferable from the viewpoint of their effect of preventingcured film coloration and preventing film thickness reduction.

Examples of commercially available antioxidants include Irganox 1010,1035, 1076 and 1222 (trade names, all manufactured by Ciba-Geigy AG);Antigene P, 3C, FR, SUMILIZER S, and SUMILIZER GA80 (trade names, allmanufactured by Sumitomo Chemical Co., Ltd.); and ADEKASTAB A070, A080and A0503 (trade names, all manufactured by Adeka Corporation). Thesecompounds may be used alone or in combination thereof.

—Polymerization Inhibitor—

The curable compound forming the resin layer 38 having an impermeabilityto oxygen preferably contains a polymerization inhibitor. The content ofthe polymerization inhibitor is 0.001 to 1% by mass, more preferably0.005 to 0.5% by mass, and still more preferably 0.008 to 0.05% by mass,with respect to all the polymerizable monomers, and changes in viscosityover time can be suppressed while maintaining a high curing sensitivityby blending the polymerization inhibitor in an appropriate amount. Thepolymerization inhibitor may be added at the time of production of thepolymerizable monomer or may be added later to the curable composition.Preferred examples of the polymerization inhibitor include hydroquinone,p-methoxyphenol, di-tert-butyl-p-cresol, pyrrogallol,tert-butylcatechol, benzoquinone,4,4′-thiobis(3-methyl-6-tert-butylphenol),2,2′-methylenebis(4-methyl-6-tert-butylphenol), cerousN-nitrosophenylhydroxyamine, phenothiazine, phenoxazine,4-methoxynaphthol, 2,2,6,6-tetramethylpiperidine-1-oxyl free radical,2,2,6,6-tetramethylpiperidine,4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical,nitrobenzene, and dimethylaniline, among which preferred isbenzoquinone, 2,2,6,6-tetramethylpiperidine-1-oxyl free radical,4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical, orphenothiazine. These polymerization inhibitors suppress generation ofpolymer impurities not only during the production of the polymerizablemonomers but also during storage of the cured composition and suppressdegradation of pattern formability during imprinting.

Further, the curable compound forming the resin layer 38 having animpermeability to oxygen preferably contains inorganic particles.Incorporation of inorganic particles can provide an enhancedimpermeability to oxygen. Examples of inorganic particles includeinorganic layered compounds such as silica particles, alumina particles,zirconium oxide particles, zinc oxide particles, titanium oxideparticles, mica, and talc. The inorganic particles are preferablyplate-like from the viewpoint of enhancing the impermeability to oxygen,and the aspect ratio (r=a/b, where a>b) of the inorganic particles ispreferably 2 or more and 1000 or less, more preferably 10 or more and800 or less, and particularly preferably 20 or more and 500 or less. Alarger aspect ratio is preferable because it has an excellent effect ofenhancing the impermeability to oxygen. However, in the case where theaspect ratio is too large, physical strength of a film or particledispersibility in a curing composition is poor.

In addition to the above-mentioned components, a releasing agent, asilane coupling agent, an ultraviolet absorber, a light stabilizer, ananti-aging agent, a plasticizer, an adhesion promoter, a thermalpolymerization initiator, a colorant, elastomer particles, a photoacidproliferating agent, a photobase generator, a basic compound, a flowadjusting agent, a defoaming agent, a dispersant, or the like may beadded to the curable compound forming the resin layer 38 having animpermeability to oxygen.

<<Resin Layer Having an Impermeability to Oxygen>>

The resin layer 38 having an impermeability to oxygen is formed byapplying and curing a resin forming coating liquid containing theabove-mentioned curable compound. The oxygen permeability at theshortest distance between adjacent fluorescent regions 35 of the resinlayer 38 satisfies 10 cc/(m²·day·atm) or less. The oxygen permeabilityat the shortest distance between adjacent fluorescent regions 35 of theresin layer 38 is preferably 1 cc/(m²·day·atm) or less and morepreferably 10⁻¹ cc/(m²·day·atm) or less. The shortest distance necessarybetween the fluorescent regions 35 varies depending on the compositionof the resin layer 38.

With respect to oxygen permeability, fm/(s·Pa) can be used as the SIunit. It is possible to carry out conversion of units as a relationshipof 1 fm/(s·Pa)=8.752 cc/(m²·day·atm). fm is read as femtometer and 1fm=10⁻¹⁵ m.

Depending on the composition of the resin layer 38, the shortestdistance necessary between the fluorescent regions 35 varies. Theshortest distance between adjacent fluorescent regions 35 of the resinlayer 38 refers to the shortest distance in the film plane between theresin and the phosphor region in the case where it is observed from thephosphor-containing film main surface. In the following description, theshortest distance between adjacent fluorescent regions 35 of the resinlayer 38 may be referred to as the width of the resin layer.

As described above, the shortest distance necessary between the phosphorregions 35 varies depending on the composition of the resin layer 38,but as an example, the shortest distance between adjacent fluorescentregions 35 of the resin layer 38, that is, the width of the resin layeris preferably 0.001 mm or more and 3 mm or less, more preferably 0.01 mmor more and 2 mm or less, and particularly preferably 0.03 mm or moreand 2 mm or less. In the case where the width of the resin layer is tooshort, it is difficult to secure the necessary oxygen permeability, andin the case where the width of the resin layer is too long, luminanceunevenness of a display device is deteriorated, which is not preferable.

The ratio of the volume Vp of the fluorescent region to the volume Vb ofthe resin layer can be arbitrary, but the ratio of the volume Vp of thefluorescent region to the volume (Vp+Vb) of the entirephosphor-containing layer is 0.1≤Vp/(Vp+Vb)<0.9, more preferably0.2≤Vp/(Vp+Vb)<0.85, and particularly preferably 0.3≤Vp/(Vp+Vb)<0.8. Inthe case where the volume ratio of the fluorescent region is too small,the initial luminance at a certain thickness tends to decrease, and inthe case where the volume ratio of the fluorescent region is too large,the width of the resin layer becomes short, and as a result, it becomesdifficult to secure the necessary oxygen permeability. Note that aregion Vp containing phosphors and a region Vb of a resin layer havingan oxygen impermeability are defined as being multiplied by each areaand thickness in the case where observed from the phosphor-containingfilm main surface.

—Substrate Film—

The substrate films 10 and 20 are preferably a film having a function ofsuppressing permeation of oxygen. The above-mentioned embodiment has aconfiguration in which the barrier layers 12 and 22 are provided on onesurface of the support films 11 and 21, respectively. In such anembodiment, the presence of the support films 11 and 21 improves thestrength of the phosphor-containing film and makes it possible to easilyperform film formation. In the present embodiment, the barrier layers 12and 22 are provided on one surface of the support films 11 and 21, butthe substrate film may be constituted by only a support havingsufficient barrier properties.

The substrate films 10 and 20 have a total light transmittance in thevisible light region of preferably 80% or more and more preferably 85%or more. The visible light region refers to a wavelength region of 380to 780 nm, and the total light transmittance refers to an average valueof light transmittances over the visible light region.

The oxygen permeability of the substrate films 10 and 20 is preferably1.00 cc/(m²·day·atm). The oxygen permeability is more preferably 0.1cc/(m²·day·atm) or less, still more preferably 0.01 cc/(m²·day·atm) orless, and particularly preferably 0.001 cc/(m²·day·atm) or less. Theoxygen permeability here is a value measured using an oxygen gaspermeability measuring apparatus (OX-TRAN 2/20, trade name, manufacturedby MOCON Inc.) under conditions of a measurement temperature of 23° C.and a relative humidity of 90%.

In addition to having a gas barrier function of blocking oxygen, thesubstrate films 10 and 20 preferably have a function of blockingmoisture (water vapor). The moisture permeability (water vaporpermeability) of the substrate films 10 and 20 is preferably 0.10g/(m²·day·atm) or less and more preferably 0.01 g/(m²·day·atm) or less.

(Support Film)

The support films 11 and 21 are preferably a flexible belt-like supportwhich is transparent to visible light. The phrase “transparent tovisible light” as used herein refers to a light transmittance in thevisible light region of 80% or more and preferably 85% or more. Thelight transmittance for use as a measure of transparency can becalculated by the method described in JIS-K7105, namely, by measuring atotal light transmittance and an amount of scattered light using anintegrating sphere type light transmittance analyzer, and subtractingthe diffuse transmittance from the total light transmittance. Withrespect to the flexible support, reference can be made to paragraphs[0046] to [0052] of JP2007-290369A and paragraphs [0040] to [0055] ofJP2005-096108A.

The support film preferably has barrier properties against oxygen andmoisture. Preferred examples of such a support film include apolyethylene terephthalate film, a film made of a polymer having acyclic olefin structure, and a polystyrene film.

From the viewpoint of gas barrier properties, impact resistance, and thelike, the thickness of the support film is preferably in the range of 10to 500 μm, inter alia, preferably in the range of 15 to 300 μm,particularly preferably in the range of 15 to 120 μm, more particularlypreferably in the range of 15 to 100 μm, further preferably 25 to 110μm, and more further preferably 25 to 60 μm.

(Barrier Layer)

The substrate films 10 and 20 preferably include barrier layers 12 and22 containing at least one inorganic layer formed in contact with thesurface of the support films 11 and 21 on the phosphor-containing layer30 side. The barrier layers 12 and 22 may include at least one inorganiclayer and at least one organic layer. Lamination of a plurality oflayers in this way is preferable from the viewpoint of improving thelight resistance due to being capable of further more enhancing barrierproperties. On the other hand, the light transmittance of the substratefilm tends to decrease as the number of layers to be laminated isincreased, and therefore it is desirable to increase the number oflaminated layers as long as a satisfactory light transmittance can bemaintained.

Specifically, the barrier layers 12 and 22 preferably have a total lighttransmittance in the visible light region of preferably 80% or more andan oxygen permeability of 1.00 cc/(m²·day·atm) or less.

The oxygen permeability of the barrier layers 12 and 22 is morepreferably 0.1 cc/(m²·day·atm) or less, particularly preferably 0.01cc/(m²·day·atm) or less, and more particularly preferably 0.001cc/(m²·day·atm) or less.

A lower oxygen permeability is more preferable, and a higher total lighttransmittance in the visible light region is more preferable.

The inorganic layer is a layer containing an inorganic material as amain component, and preferably a layer formed from only an inorganicmaterial.

The inorganic layer is preferably a layer having a gas barrier functionof blocking oxygen. Specifically, the oxygen permeability of theinorganic layer is preferably 1.00 cc/(m²·day·atm) or less. The oxygenpermeability of the inorganic layer can be determined by attaching awavelength converting layer to a detector of an oxygen concentrationmeter manufactured by Orbisphere Laboratories, via silicone grease, andthen converting the oxygen permeability from the equilibrium oxygenconcentration value. It is also preferred that the inorganic layer has afunction of blocking water vapor.

Two or three or more inorganic layers may also be included in thebarrier layer.

The thickness of the inorganic layer may be 1 to 500 nm, and ispreferably 5 to 300 nm and particularly preferably 10 to 150 nm. This isbecause the film thickness of an adjacent inorganic layer in theabove-specified range is capable of suppressing reflection on theinorganic layer while achieving satisfactory barrier properties, wherebya laminated film with higher light transmittance can be provided.

In the substrate film, it is preferred that at least one inorganic layeradjacent to the phosphor-containing layer is included.

The inorganic material constituting the inorganic layer is notparticularly limited, and for example, a metal, or various inorganiccompounds such as inorganic oxides, nitrides or oxynitrides can be usedtherefor. For element(s) constituting the inorganic material, silicon,aluminum, magnesium, titanium, tin, indium, and cerium are preferable,and these elements may be included singly or two or more thereof may beincluded. Specific examples of the inorganic compound include siliconoxide, silicon oxynitride, aluminum oxide, magnesium oxide, titaniumoxide, tin oxide, an indium oxide alloy, silicon nitride, aluminumnitride, and titanium nitride. As the inorganic layer, a metal film, forexample, an aluminum film, a silver film, a tin film, a chromium film, anickel film, or a titanium film may also be provided.

It is particularly preferred that the inorganic layer having barrierproperties is an inorganic layer containing at least one compoundselected from silicon nitride, silicon oxynitride, silicon oxide, andaluminum oxide, among the above-mentioned materials. This is because theinorganic layer formed of such a material is satisfactory inadhesiveness to the organic layer, and therefore, not only, even in thecase where the inorganic layer has a pinhole, the organic layer caneffectively fill in the pinhole to suppress fracture, but also, even inthe case where the inorganic layer is laminated, an extremelysatisfactory inorganic layer film can be formed to result in a furtherenhancement in barrier properties.

The organic layer refers to a layer containing an organic material as amain component, in which the organic material preferably occupies 50% bymass or more, further preferably 80% by mass or more, and particularlypreferably 90% by mass or more.

With respect to the organic layer, reference can be made to paragraphs[0020] to [0042] of JP2007-290369A and paragraphs [0074] to [0105] ofJP2005-096108A. It is preferred that the organic layer contains a cardopolymer within a range satisfying the above-mentioned adhesion forceconditions. This is because adhesiveness to the layer adjacent to theorganic layer, in particular, also adhesiveness to the inorganic layercan be thus improved to achieve excellent gas barrier properties. Withrespect to details of the cardo polymer, reference can be made toparagraphs [0085] to [0095] of JP2005-096108A described above. The filmthickness of the organic layer is preferably in the range of 0.05 to 10μm, inter alia, preferably in the range of 0.5 to 10 μm. In the casewhere the organic layer is formed by a wet coating method, the filmthickness of the organic layer is preferably in the range of 0.5 to 10μm, inter alia, preferably in the range of 1 to 5 μm. In the case wherethe organic layer is formed by a dry coating method, the film thicknessof the organic layer is preferably in the range of 0.05 to 5 μm, interalia, preferably in the range of 0.05 to 1 μm. This is because the filmthickness of the organic layer formed by a wet coating method or a drycoating method in the above-specified range is capable of furtherimproving adhesiveness to the inorganic layer.

With respect to other details of the inorganic layer and the organiclayer, reference can be made to the descriptions of JP2007-290369A andJP2005-096108A described above and US2012/0113672A1.

<Production Method of Phosphor-Containing Film>

Next, an example of production steps of the phosphor-containing films 1and 2 according to the embodiment of the present invention configured asdescribed above will be described with reference to FIG. 12.

(Coating Liquid Preparation Step)

In the first coating liquid preparation step, a fluorescent regionforming coating liquid containing quantum dots (or quantum rods) asphosphors is prepared. Specifically, individual components such asquantum dots, a curable compound, a thixotropic agent, a polymerizationinitiator, and a silane coupling agent dispersed in an organic solventare mixed in a tank or the like to prepare a fluorescent region formingcoating liquid. Note that the fluorescent region forming coating liquidmay not contain an organic solvent.

In the second coating liquid preparation step, a resin layer coatingliquid to be filled between the fluorescent regions is prepared.

(Fluorescent Region Forming Step)

Next, predetermined pattern printing is carried out on the barrier layer12 of the first substrate film 10 using the fluorescent region formingcoating liquid 32 (51), and the solvent is evaporated as necessary, sothat the fluorescent region forming coating liquid 32 is cured to form afluorescent region 35 (S2).

(Resin Layer Forming Step)

The resin layer coating liquid 37 is applied and filled between thefluorescent regions 35 (S3). Thereafter, the resin layer coating liquid37 is cured to form a resin layer 38 having an impermeability to oxygen(S4).

With respect to the curing treatment in the fluorescent region formingstep and the resin filling step, thermal curing, photocuring withultraviolet light, or the like may be appropriately selected dependingon the coating liquid.

Further, the fluorescent region forming step and the resin layer formingstep may be reversed in order. That is, after patterning the resin layercoating liquid 37 for forming the resin layer 38 having animpermeability to oxygen, the phosphor region forming coating liquid maybe filled.

Through the above steps, the phosphor-containing film 1 of the firstembodiment can be produced.

It should be noted that, after coating the resin layer coating liquid 37and before curing thereof, the second substrate film, which is woundaround a lamination roller and conveyed, and the above-mentionedphosphor-containing film 1, which is wound around a backup roller andconveyed, are sandwiched and nipped between the lamination roller andthe backup roller to perform a lamination step in which a film islaminated on the coated surface side of the coating film, and then thecoating liquid 37 is cured, whereby a phosphor-containing film 2 of thesecond embodiment can be produced (S5).

(Cutting Process)

A continuous (long) phosphor-containing film can be obtained byperforming the above steps in a roll-to-roll type apparatus. Theobtained phosphor-containing film is cut by a cutting machine asnecessary.

In the case where a phosphor-containing film having a desired size isproduced from a long film as described above, only one region containingphosphors may be present in the phosphor-containing film obtained aftercutting. As shown in FIG. 13, a plurality of fluorescent regions 35having a desired length in the longitudinal direction of the long filmare formed so as to have only one phosphor-containing region in thewidth direction of the long film with a distance d in the lengthdirection L, a long phosphor-containing film 8 provided with aphosphor-containing layer filled with a resin layer 38 having animpermeability to oxygen between the fluorescent regions and at bothends in the width direction W is formed, and cutting is carried out at aportion of the resin layer 38 between the fluorescent regions 35, forexample, at a portion indicated by a broken line D in FIG. 13, wherebythe phosphor-containing film 9 in which only one fluorescent region 35is present and the fluorescent region 35 is surrounded by a resin can beproduced.

Here, in the case where the resin layer forming step is carried outbefore the fluorescent region forming step, that is, in the case wherethe resin layer 38 having an impermeability to oxygen is formed prior tothe fluorescent region, a method of forming a pattern (in particular, afine convex and concave pattern) using a curable compound for formingthe resin layer 38 will be described.

To form a pattern, a so-called photoimprinting method of forming a fineconvex and concave pattern through a step of applying a curable compoundforming a resin layer 38 having an impermeability to oxygen onto asubstrate or a support (base material), a step of pressing a moldagainst the surface of the coating layer, a step of irradiating thecurable compound with light, and a step of peeling a mold can be used.

Here, the curable compound forming the resin layer 38 having animpermeability to oxygen may be poured between the base material and themold, and then photo-cured while pressing the mold under pressure.Further, the curable compound may be further heated and cured afterphoto-irradiation. Such photoimprint lithography is also capable ofachieving lamination or multiple patterning and may be used incombination with thermal imprinting.

The pattern formation can also be carried out by an inkjet method or adispenser method.

Hereinafter, the convex and concave pattern forming method (patterntransfer method) will be specifically described.

First, a curable compound is applied onto a base material. The methodsof applying a curable compound onto the base material include commonlywell-known application methods such as dip coating, air knife coating,curtain coating, wire bar coating, gravure coating, extrusion coating,spin coating, slit scanning, casting, and ink jet methods, by which acoated film or liquid droplets may be applied onto the base material.The curable compound forming the resin layer 38 having an impermeabilityto oxygen is suitable for a gravure coating method and a casting method.The film thickness of the pattern forming layer (coating layer forforming a pattern) formed of the curable compound varies depending onthe application to be used, but it is about 1 to 150 μm. Alternatively,the curable compound may be coated by multiple coating. Further, anotherorganic layer such as a planarizing layer may be formed between the basematerial and the pattern forming layer. The pattern forming layer andthe substrate are therefore not brought into direct contact with eachother, so that the substrate may be prevented from adhesion of dust,damage, and the like.

The base material for transfer (substrate or support) for applying acurable compound is selectable depending on various applications, andexamples thereof include, but are not particularly limited to, quartz,glass, optical film, ceramic material, vapor deposited film, magneticfilm, reflective film, metal substrate made of Ni, Cu, Cr, Fe or thelike, paper, Spin On Glass (SOG), polymer substrates such as polyesterfilm, polycarbonate film, or polyimide film, TFT array substrate,electrode plate of PDP, glass or translucent plastic substrate,electro-conductive base material made of ITO, metal, or the like,insulating base material, and semiconductor manufacturing substrate madeof silicon, silicon nitride, polysilicon, silicon oxide, amorphoussilicon, or the like. The shape of the base material is also notparticularly limited, and may be any of a plate-like substrate or aroll-like substrate. Further, as described below, the base material maybe selected from translucent and non-translucent ones, depending on acombination with a mold or the like.

Next, in order to transfer the pattern to the pattern forming layer, themold is pressed onto the surface of the pattern forming layer. In thisway, a fine pattern preliminarily formed on the surface, to be pressed,of the mold may be transferred to the pattern forming layer.Alternatively, a curable compound may be applied onto a mold having apattern formed thereon, and the substrate may be pressed thereto. Forphotoimprint lithography, a light-transmissive material is selected forat least one of the mold material and/or the base material. In thephotoimprint lithography, a curable compound is applied onto a basematerial to form a pattern forming layer thereon, and alight-transmissive mold is pressed against the surface of the patternforming layer, then this is irradiated with light from the back of themold, and the curable compound is thereby cured. Alternatively, acurable compound is applied onto a light-transmissive base material,then a mold is pressed against the surface of the coating layer, andthis is irradiated with light from the back of the base material wherebythe curable compound can be cured.

The photo-irradiation may be carried out in a state in which the mold isattached or after the mold is peeled off, but it is preferable toperform photo-irradiation in a state where the mold is in close contact.

The mold usable herein is a mold having formed thereon a pattern to betransferred. The pattern on the mold may be formed according to desiredprocessing accuracy, for example, by photolithography, electron beamlithography, or the like, but the method of forming a mold pattern isnot particularly limited.

The light-transmissive molding material is not particularly limited, butany material having predetermined strength and durability may be used.Specific examples thereof include glass, quartz, a light-transparentresin such as PMMA or polycarbonate resin, a transparent metaldeposition film, a flexible film made of polydimethylsiloxane or thelike, a photocured film, and a metal film such as SUS.

On the other hand, the non-light transmissive mold material used in thecase of using a light transmissive base material is not particularlylimited, but any material having a predetermined strength may be used.Specific examples of the mold material include a ceramic material, avapor deposited film, a magnetic film, a reflective film, a metalsubstrate such as Ni, Cu, Cr, Fe or the like, and a substrate of SiC,silicon, silicon nitride, polysilicon, silicon oxide, amorphous siliconor the like. Further, the shape of the mold is not particularly limited,either a plate-like mold or a roll-like mold may be used. The roll-likemold is applied particularly in the case where continuous productivityof transfer is required.

A mold may be used which has been subjected to a surface releasetreatment in order to improve releasability between the curable compoundand the mold surface. As such a mold, those treated with a silanecoupling agent such as a silicone-based silane coupling agent or afluorine-based silane coupling agent, for example, commerciallyavailable releasing agents such as OPTOOL DSX (manufactured by DaikinIndustries, Ltd.) and Novec EGC-1720 (manufactured by Sumitomo 3M Ltd.)can also be suitably used.

In the case where such photoimprint lithography is carried out, it isusually preferable to carry out the lithography at a molding pressure of10 atm or less. In the case where the mold pressure is set to 10 atm orless, the mold and the substrate are hardly deformed and the patternaccuracy tends to improve. In addition, it is preferable from theviewpoint that the pressure unit may be small-sized since the pressureto be given to the mold may be low. Regarding the mold pressure, it ispreferable to select a region where uniformity of mold transfer can besecured within the range where the residual film of the curable compoundin the area of mold pattern projections is reduced.

The irradiation dose of photo-irradiation in the step of irradiating thepattern forming layer with light may be sufficiently larger than theirradiation dose necessary for curing. The irradiation dose necessaryfor curing is appropriately determined by examining the consumptionamount of unsaturated bonds of the curable composition and the tackinessof the cured film.

In the photoimprint lithography, photo-irradiation is carried out whilekeeping the substrate temperature generally at room temperature, inwhich the photo-irradiation may alternatively be conducted under heatingfor the purpose of enhancing the reactivity. The photo-irradiation maybe carried out in vacuo, since a vacuum conditioning prior to thephoto-irradiation is effective for preventing entrainment of bubbles,suppressing the reactivity from being reduced due to incorporation ofoxygen, and for improving the adhesiveness between the mold and thecurable composition. In the pattern forming method, the degree of vacuumat the time of photo-irradiation is preferably in the range of 10⁻¹ Pato 1 atmosphere.

The light used for curing the curable compound is not particularlylimited, and examples thereof include light and radiation having awavelength falling within a range of high-energy ionizing radiation,near ultraviolet light, far ultraviolet light, visible light, infraredlight, and the like. The high-energy ionizing radiation source includes,for example, accelerators such as a Cockcroft accelerator, a Van deGraaff accelerator, a linear accelerator, a betatron, and a cyclotron.The electron beams accelerated by such an accelerator are usedindustrially most conveniently and economically; but any otherradioisotopes and other radiations from nuclear reactors, such as γrays, X rays, a rays, neutron beams, and proton beams may also be used.Examples of the ultraviolet ray source include an ultravioletfluorescent lamp, a low-pressure mercury lamp, a high-pressure mercurylamp, an ultra-high-pressure mercury lamp, a xenon lamp, a carbon arclamp, a solar lamp, and a light emitting diode (LED). Examples of theradiation include microwaves and extreme ultraviolet (EUV). In addition,laser light used in microfabrication of semiconductors, such as LED,semiconductor laser light, 248 nm KrF excimer laser light, and 193 nmArF excimer laser light, can also be suitably used in the presentinvention. These lights may be monochromatic lights, or may also belights of different wavelengths (mixed lights).

Upon exposure, the exposure illuminance is preferably within a range of1 mW/cm² to 50 mW/cm². In the case where the exposure illuminance is setto 1 mW/cm² or more, then the productivity may increase since theexposure time may be reduced; and in the case where the exposureilluminance is set to 50 mW/cm² or less, then it is favorable since theproperties of a permanent film may be prevented from being degradedowing to side reactions. The exposure dose is preferably in the range of5 mJ/cm² to 1,000 mJ/cm². In the case where the exposure dose is lessthan 5 mJ/cm², the exposure margin becomes narrow and the photocuringbecomes insufficient so that problems such as adhesion of unreactedmaterials to the mold are liable to occur. On the other hand, in thecase where the exposure dose is more than 1,000 mJ/cm², there is a riskof deterioration of the permanent film due to decomposition of thecomposition. Further, at the time of exposure, in order to preventinhibition of radical polymerization by oxygen, an inert gas such asnitrogen or argon may be flowed to control the oxygen concentration tobe less than 100 mg/L.

In the pattern forming method, after the pattern forming layer is curedthrough photo-irradiation, a step of further curing the cured pattern byapplying heat thereto may be included as necessary. The temperature ofheat for heating and curing the composition of the present inventionafter photo-irradiation is preferably 150° C. to 280° C. and morepreferably 200° C. to 250° C. The heating time is preferably 5 to 60minutes and more preferably 15 to 45 minutes.

The pattern to be formed may take an arbitrary form. For example, thereis a grid-like mesh pattern in which a concave or convex portion is of aregular tetragon, a honeycomb pattern in which a concave or convexportion is of a regular hexagon, or a sea island pattern in which aconcave or convex portion is circular. A honeycomb pattern having aphosphor-containing layer in a regular hexagonal portion and a resinlayer in a peripheral portion is particularly preferable from theviewpoint of effectively blocking penetration of oxygen into a phosphorlayer with respect to an arbitrary cutting form of the presentinvention.

“Backlight Unit”

With reference to the drawings, a description will be given of abacklight unit including a wavelength converting member as oneembodiment of the phosphor-containing film of the present invention.FIG. 14 is a schematic diagram showing a schematic configuration of abacklight unit.

As shown in FIG. 14, the backlight unit 102 includes a planar lightsource 101C including a light source 101A that emits primary light (bluelight L_(B)) and a light guide plate 101B that guides and emits primarylight emitted from the light source 101A, a wavelength converting member100 made of a phosphor-containing film provided on the planar lightsource 101C, a reflecting plate 102A disposed opposite to the wavelengthconverting member 100 with the planar light source 101C interposedtherebetween, and a retroreflective member 102B. In FIG. 14, thereflecting plate 102A, the light guide plate 101B, the wavelengthconverting member 100, and the retroreflective member 102B are separatedfrom each other, but in reality these are formed in close contact witheach other.

The wavelength converting member 100 emits fluorescence by using atleast a part of the primary light L_(B) emitted from the planar lightsource 101C as excitation light and emits the secondary light (greenlight L_(G), and red light L_(R)) composed of this fluorescence and theprimary light L_(B) transmitted through the wavelength converting member100.

For example, the wavelength converting member 100 is aphosphor-containing film which is constituted such that thephosphor-containing layers including the quantum dots that emit thegreen light L_(G) and the quantum dots that emit the red light L_(R)upon irradiation with the blue light L_(B) are sandwiched between thefirst and second substrate films.

In FIG. 14, L_(B), L_(G), and L_(R) emitted from the wavelengthconverting member 100 are incident on the retroreflective member 102B,and each incident light repeats reflection between the retroreflectivemember 102B and the reflecting plate 102A and passes through thewavelength converting member 100 many times. As a result, in thewavelength converting member 100, a sufficient amount of excitationlight (blue light L_(B)) is absorbed by the phosphors 31 (in this case,quantum dots) in the phosphor-containing layer 30 and a necessary amountof fluorescence (L_(G), and L_(R)) is emitted, and the white light L_(W)is embodied from the retroreflective member 102B and is emitted.

From the viewpoint of realizing high luminance and high colorreproducibility, it is preferred to use, as the backlight unit, oneformed into a multi-wavelength light source. For example, preferred is abacklight unit which emits blue light having a luminescence centerwavelength in the wavelength band of 430 to 480 nm and having anluminescence intensity peak with a half width of 100 nm or less, greenlight having a luminescence center wavelength in the wavelength band of500 to 600 nm and having an luminescence intensity peak with a halfwidth of 100 nm or less, and red light having a luminescence centerwavelength in the wavelength band of 600 to 680 nm and having anluminescence intensity peak with a half width of 100 nm or less.

From the viewpoint of further improving luminance and colorreproducibility, the wavelength band of the blue light emitted from thebacklight unit is more preferably 440 nm to 460 nm.

From the same viewpoint, the wavelength band of the green light emittedfrom the backlight unit is preferably 520 nm to 560 nm and morepreferably 520 nm to 545 nm.

In addition, from the same viewpoint, the wavelength band of the redlight emitted from the backlight unit is more preferably 610 nm to 640nm.

In addition, from the same viewpoint, all the half widths of therespective luminescence intensities of the blue light, the green light,and the red light emitted from the backlight unit are preferably 80 nmor less, more preferably 50 nm or less, further preferably 40 nm orless, still more preferably 30 nm or less. Among them, the half width ofthe luminescence intensity of the blue light is particularly preferably25 nm or less.

In the above description, the light source 101A is, for example, a bluelight emitting diode that emits blue light having a luminescence centerwavelength in the wavelength band of 430 nm to 480 nm, but anultraviolet light emitting diode that emits ultraviolet light may beused. As the light source 101A, a laser light source or the like may beused in addition to light emitting diodes. In the case where a lightsource that emits ultraviolet light is provided, the wavelengthconverting layer (phosphor-containing layer) of the wavelengthconverting member may include a phosphor that emits blue light, aphosphor that emits green light, and a phosphor that emits red light,upon irradiation with ultraviolet light.

As shown in FIG. 14, the planar light source 101C may be a planar lightsource formed of the light source 101A, and the light guide plate 101Bwhich guides the primary light exiting from the light source 101A andallows the guided primary light to exit, or may be a planar light sourcein which the light source 101A and the wavelength converting member 100are disposed parallel to each other on the plane, and a diffusion plateis provided in place of the light guide plate 101B. The former planarlight source is generally referred to as an edge light mode backlightunit, and the latter planar light source is generally referred to as adirect backlight mode backlight unit.

In the present embodiment, the case where a planar light source is usedas a light source has been described as an example, but a light sourceother than the planar light source may also be used as the light source.

(Configuration of Backlight Unit)

In FIG. 14, an edge light mode backlight unit including a light guideplate, a reflecting plate, and the like as constituent members has beenillustrated as the configuration of the backlight unit, but thebacklight unit may be a direct backlight mode backlight unit. A knownlight guide plate can be used as the light guide plate without anylimitation.

In addition, the reflecting plate 102A is not particularly limited, andknown reflecting plates can be used, which are described in JP3416302B,JP3363565B, JP4091978B, and JP3448626B, and the like, the contents ofwhich are incorporated by reference herein in their entirety.

The retroreflective member 102B may be configured of a known diffusionplate or a known diffusion sheet, a known prism sheet (for example, BEFseries manufactured by Sumitomo 3M Limited), a known light guide device,and the like. The configuration of the retroreflective member 102B isdescribed in JP3416302B, JP3363565B, JP4091978B, JP3448626B, and thelike, the contents of which are incorporated by reference herein intheir entirety.

“Liquid Crystal Display”

The backlight unit 102 described above can be applied to a liquidcrystal display. As shown in FIG. 15, a liquid crystal display 104includes the backlight unit 102 of the above-described embodiment, and aliquid crystal cell unit 103 disposed opposite to the retroreflectivemember side of the backlight unit.

As shown in FIG. 15, the liquid crystal cell unit 103 has aconfiguration in which a liquid crystal cell 110 is sandwiched betweenpolarizing plates 120 and 130, and the polarizing plates 120 and 130 areconfigured such that both main surfaces of polarizers 122 and 132 areprotected by polarizing plate protective films 121 and 123, and 131 and133, respectively.

The liquid crystal cell 110 and the polarizing plates 120 and 130constituting the liquid crystal display 104 and the constituents thereofare not particularly limited, and members prepared by a known method orcommercially available products can be used without any limitation. Inaddition, it is also possible, of course, to provide a knownintermediate layer such as an adhesive layer between the respectivelayers.

A driving mode of the liquid crystal cell 110 is not particularlylimited, and various modes such as a twisted nematic (TN) mode, a supertwisted nematic (STN) mode, a vertical alignment (VA) mode, an in-planeswitching (IPS) mode, and an optically compensated bend cell (OCB) modecan be used. The driving mode of the liquid crystal cell is preferably aVA mode, an OCB mode, an IPS mode, or a TN mode, but it is not limitedthereto. An example of the configuration of the liquid crystal displayin the VA mode may be the configuration illustrated in FIG. 2 ofJP2008-262161A. Here, a specific configuration of the liquid crystaldisplay is not particularly limited, and a known configuration can beadopted.

Further, as necessary, the liquid crystal display 104 includes asubsidiary functional layer such as an optical compensation memberperforming optical compensation or an adhesive layer. In addition, asurface layer such as a forward scattering layer, a primer layer, anantistatic layer, or an undercoat layer may be disposed along with (orin place of) a color filter substrate, a thin layer transistorsubstrate, a lens film, a diffusion sheet, a hard coat layer, anantireflection layer, a low reflective layer, an antiglare layer, or thelike.

The backlight side polarizing plate 120 may include a phase differencefilm as a polarizing plate protective film 123 on the liquid crystalcell 110 side. A known cellulose acylate film or the like can be used assuch a phase difference film.

The backlight unit 102 and the liquid crystal display 104 are providedwith the wavelength converting member made of the phosphor-containingfilm of the present invention described above in which oxygendeterioration is suppressed. Accordingly, the same effect as that of theabove-mentioned phosphor-containing film of the present invention can beobtained, and a high-luminance backlight unit and a high-luminanceliquid crystal display, in which the luminescence intensity of thewavelength converting layer containing quantum dots is hardly lowered,are obtained.

EXAMPLES

Hereinafter, the present invention will be more specifically describedwith reference to Examples. The materials, use amounts, proportions,treatment contents, treatment procedures, and the like shown in thefollowing Examples can be appropriately modified without departing fromthe spirit of the present invention. Therefore, the scope of the presentinvention should not be construed as being limited to the followingspecific Examples.

Example 1

<Method for Producing Phosphor-Containing Film>

A method for producing a phosphor-containing film having aphosphor-containing layer by using a coating liquid containing quantumdots as phosphors will be described.

(Substrate Film)

As a first substrate film and a second substrate film, a substrate filmwas prepared in which a barrier layer made of an inorganic layer wasformed on a support film formed of polyethylene terephthalate (PET), andan organic layer coated with the following composition was formed on thebarrier layer. The thickness of the inorganic layer was 10 nm.

((Composition for Substrate Film Organic Layer))

Urethane acrylate 30 parts by mass (ACRIT 8BR-500, manufactured byTaisei Fine Chemical Co., Ltd.) Photopolymerization initiator 3 parts bymass (IRGACURE 184, manufactured by BASF GmbH) Methyl isobutyl ketone 67parts by mass

The above composition was coated on the barrier layer of the supportfilm to a thickness of 1 μm and then dried at 60° C. for 1 minute. Usingan air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.)at 200 W/cm, ultraviolet rays at a dose of 400 mJ/cm² were irradiatedfrom the coated surface to cure the dried film, thus forming an organiclayer.

(Preparation of Phosphor-Containing Layer)

As a coating liquid 1 for forming a phosphor-containing layer,individual components such as a quantum dot, a curable compound, athixotropic agent, a polymerization initiator, and a silane couplingagent were mixed in a tank or the like to prepare a coating liquid.

<Composition of Coating Liquid 1 of Phosphor-Containing Layer>

A quantum dot dispersion liquid having the following composition wasprepared and used as coating liquid 1. Toluene dispersion liquid ofquantum dots 1 10 parts by mass (emission maximum: 520 nm) Toluenedispersion liquid of quantum dots 2 1 part by mass (emission maximum:630 nm) Lauryl methacrylate 2.4 parts by mass Trimethylolpropanetriacrylate 0.54 parts by mass Photopolymerization initiator 0.009 partsby mass (IRGACURE 819, manufactured by BASF GmbH)

For the quantum dots 1 and 2, nanocrystals having the followingcore-shell structure (InP/ZnS) were used.

-   -   Quantum dots 1: INP 530-10 (manufactured by NN-Labs, LLC)    -   Quantum dots 2: INP 620-10 (manufactured by NN-Labs, LLC)

A coating liquid not containing quantum dots 1 and 2 in theabove-mentioned coating liquid 1 was prepared as the coating liquid 2for forming a resin layer filled between the fluorescent regions.

The resins used for coating liquid 1 and coating liquid 2 were the samein this Example, but they may be different.

(Coating Step)

In the case of using the resin formed from the coating liquid of theabove-mentioned formulation, a fluorescent region pattern in adistance-separated arrangement capable of obtaining oxygen permeabilitybetween fluorescent regions shown in Table 1 below was formed by screenprinting using the coating liquid 1. Thereafter, the solvent was driedto thermally cure the film at 80° C. for 10 minutes, the coating liquid2 was applied by screen printing so as to fill the space between thefluorescent regions, and the solvent was dried to thermally cure thefilm at 80° C. for 10 minutes.

Here, the thickness of the phosphor-containing layer was 50 μm, thefluorescent region was of a square shape of 1 mm (=Q) on one side, thefluorescent regions were two-dimensionally disposed through a resinlayer having a line width of 0.5 mm (═S), and the resin layer was of asquare grid pattern.

Then, the inorganic layer of the second substrate film was laminated tothe coated surfaces of the first and second coating liquids. Using anair-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) at200 W/cm, ultraviolet rays at a dose of 1,000 mJ/cm² were thenirradiated from the coated surface to cure the film which was furtherheated at 80° C. for 10 minutes to thermally cure the film, whereby aphosphor-containing film was prepared. The thickness of thephosphor-containing layer of the obtained phosphor-containing film was50 μm.

Example 2

A phosphor-containing film was prepared in the same manner as in Example1, except that the composition described below was used as the coatingliquid for forming a resin layer.

<Composition of Coating Liquid 3 for Forming Resin Layer>

Tricyclodecanedimethanol diacrylate 99 parts by mass (A-DCP,manufactured by Shin-Nakamura Chemical Co., Ltd.) Photopolymerizationinitiator 1 part by mass (IRGACURE 819, manufactured by BASF GmbH)

Examples 3 and 4 and Comparative Example 1

A phosphor-containing film was prepared in the same manner as in Example1, except that the oxygen permeability of the resin between the phosphorregions and the oxygen permeability of the substrate film were changedas shown in Table 1. The thickness of the inorganic layer of the firstand second substrate films used in Example 4 was 15 nm.

Comparative Examples 2 and 3

A phosphor-containing film was prepared in the same manner as in Example1, except that MORESCO MOISTURE CUT (manufactured by MorescoCorporation) was used in place of the coating liquid 2 for forming aresin layer filled between the fluorescent regions, the ultravioletirradiation dose was 6000 mJ, the heating time was 1 hour at 80° C., andthe oxygen permeability of the resin layer between the phosphor regionsand the oxygen permeability of the substrate film were changed as shownin Table 1.

Example 5

A coating liquid having the following composition was prepared as acoating liquid 3 for forming a resin layer.

<Composition of Coating Liquid 3 for Forming Resin Layer>

Tricyclodecanedimethanol diacrylate 67 parts by mass (A-DCP,manufactured by Shin-Nakamura Chemical Co., Ltd.) Urethane acrylate 20parts by mass (U-4 HA, manufactured by Shin-Nakamura Chemical Co., Ltd.)2-perfluorohexylethyl acrylate 2 parts by mass (R-1620, manufactured byDaikin Chemical Industry Co., Ltd.) Alumina particles (particlediameter: 3 μm) 10 parts by mass Photopolymerization initiator 1 part bymass (IRGACURE 819, manufactured by BASF GmbH))

(Resin Layer Forming Step)

A resin layer was formed on the first substrate film by the followingphotoimprinting method. First, using a dispenser, the coating liquid 3for forming a resin layer was poured into a space between an SUS moldhaving a mesh-like pattern with a line width of 0.5 mm in the recess, aline width of 1 mm in the protrusion, and a height of 50 μm in theprotrusion made by a photo etching method and the organic layer side ofthe first substrate film, followed by pressing thereagainst with arubber roller at a pressure of 0.3 MPa so as to discharge an excesscoating liquid, so that the mold filled with the coating liquid waslaminated on the first substrate film. Subsequently, using an air-cooledmetal halide lamp (manufactured by Eye Graphics Co., Ltd.) at 200 W/cm,ultraviolet rays at a dose of 500 mJ/cm² were irradiated from the sideof the first substrate film to cure the film, the mold was then peeledoff, and a first substrate film (hereinafter, referred to as “firstresin film layer”), on which a resin layer having a square grid pattern(hereinafter, referred to as a “patterned resin layer”) having a depthof 50 μm and a line width of an opening (mesh size) of 1 mm×1 mm wasformed, was obtained.

(Phosphor Composition Filling Step)

A phosphor layer-containing film filled between the resin layers on thefirst substrate film and laminated with the second substrate film wasprepared according to the following procedure. First, using a dispenser,the coating liquid 1 of the phosphor-containing layer was poured into aspace between the resin layer side of the first substrate film on whichthe resin layer prepared in the resin layer forming step was formed andthe organic layer side of the second substrate film, followed bypressing thereagainst with a rubber roller at a pressure of 0.3 MPa soas to discharge an excess coating liquid, so that the coating liquid ofthe phosphor-containing layer was filled between the patterned resinlayer on the first substrate film and the second substrate film. Thatis, the coating liquid for a phosphor-containing layer was filled in theopening of the patterned resin layer. Subsequently, using an air-cooledmetal halide lamp (manufactured by Eye Graphics Co., Ltd.) at 200 W/cm,ultraviolet rays were irradiated from the side of the first substratefilm at a dose of 1,000 mJ/cm² to cure the film, thus preparing aphosphor-containing film. The obtained phosphor-containing film had aresin layer width of 0.5 mm, a phosphor layer width of 1 mm, and a filmthickness of each of a resin layer and a phosphor layer of 50 μm. Theinorganic layer thickness of each of the first and second base materialswas 25 nm.

Examples 6 to 12 and Comparative Examples 4 and 5

A phosphor-containing film was prepared in the same manner as in Example5, except that the line width of the concavo-convex part of the moldmanufactured by a photo etching method was adjusted to change the linewidth of the patterned resin layer and the size of the square opening sothat the volume ratio of the phosphor region becomes the value shown inTable 1, and the oxygen permeability of the resin between the phosphorregions and the oxygen permeability of the substrate film were changedas shown in Table 1. The height of the mold convex portion was fixed at50 μm. That is, the thickness of each of the resin layer and thephosphor-containing layer of the phosphor-containing film was set to 50μm.

Example 13

A phosphor-containing film was prepared in the same manner as in Example6, except that the composition described below was used as the coatingliquid for forming a resin layer.

<Composition of Coating Liquid 3 for Forming Resin Layer>

Tricyclodecanedimethanol diacrylate 13 parts by mass (A-DCP,manufactured by Shin-Nakamura Chemical Co., Ltd.) Urethane acrylate 50parts by mass (U-4HA, manufactured by Shin-Nakamura Chemical Co., Ltd.)Epoxy methacrylate 13 parts by mass (CYCLOMER M100, manufactured byDaicel Chemical Industries, Ltd.) 2-Perfluorohexylethyl acrylate 2 partsby mass (R-1620, manufactured by Daikin Chemical Industry Co., Ltd.)Alumina particles (particle diameter: 3 μm) 10 parts by mass Sphericallight scattering particles 10 parts by mass (TOSPEARL 145, manufacturedby Momentive Performance Materials Inc., refractive index: 1.42)Photopolymerization initiator 1 part by mass (IRGACURE 819, manufacturedby BASF GmbH) Photopolymerization initiator 1 part by mass (CPI-100,manufactured by San-Apro Ltd.)

<Evaluation Items>

The phosphor-containing films prepared in Examples and ComparativeExamples were wavelength converting members, and changes over time inthe luminescence performance of these wavelength converting members weremeasured and evaluated as follows.

(Initial Luminance)

The initial luminance (Y) of the wavelength converting member of eachExample and Comparative Example was measured according to the followingprocedure. First, each wavelength converting member was cut into asquare of 1 in². Each side of the cut wavelength converting member wasparallel to the side of the square grid pattern of the resin layer. Abacklight unit was taken out by disassembling a commercially availabletablet terminal (Kindle (registered trademark) Fire HDX 7″, manufacturedby Amazon). After removing the wavelength converting member attached tothe backlight unit taken out, the phosphor-containing film prepared asdescribed above was placed on the light guide plate, and two prismsheets whose orientations were orthogonal to each other were laidthereon. Among the luminances of the light emitted from a blue lightsource and transmitted through the phosphor-containing film and the twoprism sheets, the luminance at the position 1 mm inwards from the cutsurface (however, a fluorescent region other than the fluorescent regionpositioned on the cut surface) was measured with a luminance meter (SR3,manufactured by Topcon Corporation) set at a position 740 mm apart inthe direction perpendicular to the plane of the light guide plate, andthe obtained value was taken as initial luminance (Y).

The evaluation standards for the initial luminance (Y) are as follows.In the case where the evaluation result was B or higher, it can bedetermined that the luminance efficiency was maintained satisfactorily.14000[cd/m²]<Y  AA;12000[cd/m²]<Y≤14000[cd/m²]  A;10000[cd/m²]<Y≤12000[cd/m²]  B;8000[cd/m²]<Y≤10000[cd/m²]  C;8000[cd/m²]≥Y  D;

(Evaluation of Edge Deterioration)

Next, each wavelength converting member was placed on a commerciallyavailable blue light source (OPSM-H150X142B, manufactured by OPTEX-FACo., Ltd.) in a room kept at 85° C., and the wavelength convertingmember was continuously irradiated with blue light for 2,000 hours.After 1,000 hours and 2,000 hours, the wavelength converting member wastaken out and the luminance thereof was measured according to the sameprocedure as above. The luminance at high temperature test 1,000 hoursand the luminance at high temperature test 2,000 hours were measured,respectively. Assuming that the luminance after the test is Y′, thechange rate (a) of the luminance (Y′) after the test relative to theinitial luminance value (Y) was calculated according to the followingexpression and evaluated as an index of luminance change according tothe following standards.α=Y′/Y

In the case where the evaluation results were A and B, it can bedetermined that the luminance efficiency was maintained satisfactorily.Note that the evaluation result C was practically acceptable, but theevaluation result D was unacceptable. Evaluation standards for thechange rate of the luminance after the test relative to the initialluminance value were the same also in the following deteriorationevaluation.0.95<α  A;0.7<α≤0.95  B;0.5<α≤0.7  C;0.5≥α  D;

(Evaluation of Complex Shape Edge Deterioration)

The wavelength converting members of Examples and Comparative Exampleswere cut into squares of 1 in². Each side of the cut wavelengthconverting member was set to 18° and 36° on the side of the square gridpattern of the resin layer. The luminance after 2,000 hours ofhigh-temperature test similar to the edge deterioration evaluation wasmeasured, and the result of the cutting angle having the worstevaluation in each sample was adopted as the luminance Y′ after thetest, from which the change rate (a) was determined and evaluatedaccording to the foregoing standards.

(Evaluation of Central Luminance Deterioration)

Each wavelength converting member was placed on a commercially availableblue light source (OPSM-H150X142B, manufactured by OPTEX-FA Co., Ltd.)in a room kept at 85° C., and the wavelength converting member wascontinuously irradiated with blue light for 2,000 hours. After 2,000hours, the wavelength converting member was taken out, and the luminance(Y′) at the center position of the member after the high temperaturetest was measured according to the same procedure as above and evaluatedaccording to the same judgment standards.

(Evaluation of Luminance Unevenness)

The wavelength converting member of each of Examples and ComparativeExamples cut into 50 mm² and two prism sheets mounted on a commerciallyavailable tablet terminal (Kindle (registered trademark) Fire HDX 7″,manufactured by Amazon) were placed on a commercially available bluelight source (OPSM-H150X142B, manufactured by OPTEX-FA Co., Ltd.) andthe state irradiated with blue light was photographed with a single lensreflex digital camera (D-7200, manufactured by Nikon Corporation).

In the range of 40 mm² from the sample center of the obtained image, theaverage value (G) of Gray values and the standard deviation σ wereobtained and evaluated according to the following standards. In the casewhere the evaluation results were A and B, it can be determined that theluminance unevenness was satisfactorily. Note that the evaluation resultC was practically acceptable, but the evaluation result D wasunacceptable.0%≤σ/G<3%  A:3%≤σ/G<10%  B:10%≤σ/G<20%  C:20%≥σ/G  D:

Table 1 below summarizes the differences in the conditions and theevaluation results for each example for individual Examples andComparative Examples.

As is apparent from the comparison between the Examples and ComparativeExamples 1 and 2, it is possible to improve edge luminance deteriorationin arbitrary cutting form while suppressing luminance unevenness, bysetting the width of the resin layer having an oxygen impermeability to0.01≤S<0.5 mm.

As is apparent from the comparison between Examples and ComparativeExample 1, it is possible to significantly suppress the edgedeterioration by setting the oxygen permeability coefficient of theresin having an oxygen impermeability to 10 cc·mm/(m²·day·atm) or less.

As is apparent from the comparison between Examples and ComparativeExamples 4 and 5, it is possible to maintain the initial luminance bysetting the ratio of a volume of the region Vp containing phosphors tothe sum of the volume Vp and a volume of the region Vb of the resinlayer having an oxygen impermeability to a range of 0.1≤Vp/(Vp+Vb)<0.9.

TABLE 1 Oxygen Oxygen Width S One side Q Fluorescent Initial ComplexCentral permeability of permeability of of of fluo- region lumi- EdgeEdge shape luminance Lumi- resin layer between substrate film resinrescent volume ratio nance deteri- deteri- deteri- deteri- nancefluorescent regions [cc/(m² · layer region Vp/(Vp + Y oration orationoration oration uneven- [cc/(m² · day · atm)] day · atm)] [mm] [mm] Vb)0 h 1000 h 2000 h 2000 h 2000 h ness Example 1 10  10  0.5 1 0.46 A B CC C C Example 2 1 10  0.5 1 0.46 A A B C C C Example 3 10  1  0.5 1 0.46A A B C B C Example 4 1 10⁻³ 0.5 1 0.46 A A A C A C Example 5   0.2 10⁻³0.5 1 0.46 A A A C A C Example 6   0.5 10⁻³ 0.2 1 0.68 AA A A A A AExample 7 1 10⁻³ 0.1 1 0.81 AA A A A A A Example 8 1 10⁻³ 0.1 0.1 0.30 AA A A A A Example 9   0.15 10⁻³ 0.4 3 0.76 AA A A B A B Example 10 110⁻³ 0.1 1 0.81 AA A B B A A Example 11   0.2 10⁻³ 0.45 0.3 0.22 B A B BA A Example 12 1 10⁻³ 0.1 0.8 0.78 AA A A A A A Example 13 2 10⁻³ 0.050.25 0.68 AA A A A A A Comparative 20  10  0.6 5 0.78 AA C D C C CExample 1 Comparative 10⁻³ 10⁻³ 5 — 1.00 AA A A D A A Example 2Comparative 10⁻¹ 10⁻³ 0.02 — 1.00 AA A A D A A Example 3 Comparative 110⁻³ 0.1 0.005 0.02 D A A A A A Example 4 Comparative 1 10⁻³ 0.1 0.010.04 D A A A A A Example 5

With respect to the phosphor-containing film of the present invention,the wavelength converting member has been described as an example in theforegoing embodiments, but appropriate selection of the type of thephosphor can provide applications for an organic electroluminescencelayer in an organic electroluminescence element, an organicphotoelectric conversion layer in an organic solar cell, or the like,and can achieve an effect of suppressing performance deterioration.

EXPLANATION OF REFERENCES

-   -   1, 2, 3, 4, 5, 6, 8, 9: phosphor-containing film    -   10, 20: substrate film    -   11, 21: support film    -   12, 22: barrier layer    -   30: phosphor-containing layer    -   31, 31 a, 31 b, 31 e: phosphors    -   32: coating liquid for forming fluorescent region    -   33: binder    -   35, 35K, 35 a, 35 b: region containing phosphors (fluorescent        region)    -   37: coating liquid for resin layer    -   38: resin layer having an impermeability to oxygen    -   100: wavelength converting member    -   101A: light source    -   101B: light guide plate    -   101C: planar light source    -   102: backlight unit    -   102A: reflecting plate    -   102B: retroreflective member    -   103: liquid crystal cell unit    -   104: liquid crystal display    -   110: liquid crystal cell    -   120, 130: polarizing plate    -   121, 123, 131, 133: polarizing plate protective film    -   122, 132: polarizer

What is claimed is:
 1. A phosphor-containing film, comprising: a firstsubstrate film; and a phosphor-containing layer at which a plurality ofregions containing phosphors are discretely disposed in a resin layerhaving an impermeability to oxygen, the phosphor having a property thatdeteriorates upon exposure to oxygen by reacting with the oxygen, andthe phosphor-containing layer being disposed on the first substratefilm, wherein the plurality of regions containing phosphors comprise aplurality of first fluorescent regions containing phosphors and aplurality of second fluorescent regions dispersed at different positionsin a film thickness direction from positions of the plurality of firstfluorescent regions, both the first fluorescent regions and the secondfluorescent regions being disposed in the same resin layer having animpermeability to oxygen.
 2. The phosphor-containing film according toclaim 1, wherein the plurality of first fluorescent regions containingphosphors and the plurality of second fluorescent regions containingphosphors partially overlap each other when the phosphor-containing filmis viewed in a plan view.
 3. The phosphor-containing film according toclaim 2, wherein the plurality of first fluorescent regions containingphosphors and the plurality of second fluorescent regions containingphosphors are laminated.
 4. The phosphor-containing film according toclaim 1, wherein the phosphors contained in the plurality of firstfluorescent regions and the phosphors contained in the plurality ofsecond fluorescent regions are of different kinds.
 5. Thephosphor-containing film according to claim 1, wherein the phosphorscontained in the plurality of first fluorescent regions and thephosphors contained in the plurality of second fluorescent regions areof the same kind.